DataFusion Functions

This page is generated from the Apache DataFusion project's documents:

• DataFusion Scalar Functions
• DataFusion Scalar Functions (NEW)
• DataFusion Aggregate Functions
• DataFusion Window Functions

Scalar Functions

Scalar functions operate on a single row at a time and return a single value.

Math Functions

• abs
• acos
• acosh
• asin
• asinh
• atan
• atan2
• atanh
• cbrt
• ceil
• cos
• cosh
• cot
• degrees
• exp
• factorial
• floor
• gcd
• isnan
• iszero
• lcm
• ln
• log
• log10
• log2
• nanvl
• pi
• pow
• power
• radians
• random
• round
• signum
• sin
• sinh
• sqrt
• tan
• tanh
• trunc

abs

Returns the absolute value of a number.

abs(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

acos

Returns the arc cosine or inverse cosine of a number.

acos(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

acosh

Returns the area hyperbolic cosine or inverse hyperbolic cosine of a number.

acosh(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

asin

Returns the arc sine or inverse sine of a number.

asin(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

asinh

Returns the area hyperbolic sine or inverse hyperbolic sine of a number.

asinh(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

atan

Returns the arc tangent or inverse tangent of a number.

atan(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

atan2

Returns the arc tangent or inverse tangent of expression_y / expression_x.

atan2(expression_y, expression_x)

Arguments

• expression_y: First numeric expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
• expression_x: Second numeric expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.

atanh

Returns the area hyperbolic tangent or inverse hyperbolic tangent of a number.

atanh(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

cbrt

Returns the cube root of a number.

cbrt(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

ceil

Returns the nearest integer greater than or equal to a number.

ceil(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

cos

Returns the cosine of a number.

cos(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

cosh

Returns the hyperbolic cosine of a number.

cosh(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

cot

Returns the cotangent of a number.

cot(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

degrees

Converts radians to degrees.

degrees(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

exp

Returns the base-e exponential of a number.

exp(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

factorial

Factorial. Returns 1 if value is less than 2.

factorial(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

floor

Returns the nearest integer less than or equal to a number.

floor(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

gcd

Returns the greatest common divisor of expression_x and expression_y. Returns 0 if both inputs are zero.

gcd(expression_x, expression_y)

Arguments

• expression_x: First numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression_y: Second numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

isnan

Returns true if a given number is +NaN or -NaN otherwise returns false.

isnan(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

iszero

Returns true if a given number is +0.0 or -0.0 otherwise returns false.

iszero(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

lcm

Returns the least common multiple of expression_x and expression_y. Returns 0 if either input is zero.

lcm(expression_x, expression_y)

Arguments

• expression_x: First numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression_y: Second numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

ln

Returns the natural logarithm of a number.

ln(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

log

Returns the base-x logarithm of a number. Can either provide a specified base, or if omitted then takes the base-10 of a number.

log(base, numeric_expression)
log(numeric_expression)

Arguments

• base: Base numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.
• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

log10

Returns the base-10 logarithm of a number.

log10(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

log2

Returns the base-2 logarithm of a number.

log2(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

nanvl

Returns the first argument if it's not NaN. Returns the second argument otherwise.

nanvl(expression_x, expression_y)

Arguments

• expression_x: Numeric expression to return if it's not NaN. Can be a constant, column, or function, and any combination of arithmetic operators.
• expression_y: Numeric expression to return if the first expression is NaN. Can be a constant, column, or function, and any combination of arithmetic operators.

pi

Returns an approximate value of π.

pi()

pow

Alias of power.

power

Returns a base expression raised to the power of an exponent.

power(base, exponent)

Arguments

• base: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.
• exponent: Exponent numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

Aliases

• pow

radians

Converts degrees to radians.

radians(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

random

Returns a random float value in the range [0, 1). The random seed is unique to each row.

random()

round

Rounds a number to the nearest integer.

round(numeric_expression[, decimal_places])

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.
• decimal_places: Optional. The number of decimal places to round to. Defaults to 0.

signum

Returns the sign of a number. Negative numbers return -1. Zero and positive numbers return 1.

signum(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

sin

Returns the sine of a number.

sin(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

sinh

Returns the hyperbolic sine of a number.

sinh(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

sqrt

Returns the square root of a number.

sqrt(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

tan

Returns the tangent of a number.

tan(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

tanh

Returns the hyperbolic tangent of a number.

tanh(numeric_expression)

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

trunc

Truncates a number to a whole number or truncated to the specified decimal places.

trunc(numeric_expression[, decimal_places])

Arguments

• numeric_expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.
• decimal_places: Optional. The number of decimal places to truncate to. Defaults to 0 (truncate to a whole number). If decimal_places is a positive integer, truncates digits to the right of the decimal point. If decimal_places is a negative integer, replaces digits to the left of the decimal point with 0.

Conditional Functions

• coalesce
• greatest
• ifnull
• least
• nullif
• nvl
• nvl2

coalesce

Returns the first of its arguments that is not null. Returns null if all arguments are null. This function is often used to substitute a default value for null values.

coalesce(expression1[, ..., expression_n])

Arguments

• expression1, expression_n: Expression to use if previous expressions are null. Can be a constant, column, or function, and any combination of arithmetic operators. Pass as many expression arguments as necessary.

Example

> select coalesce(null, null, 'datafusion');
+----------------------------------------+
| coalesce(NULL,NULL,Utf8("datafusion")) |
+----------------------------------------+
| datafusion                             |
+----------------------------------------+

greatest

Returns the greatest value in a list of expressions. Returns null if all expressions are null.

greatest(expression1[, ..., expression_n])

Arguments

• expression1, expression_n: Expressions to compare and return the greatest value.. Can be a constant, column, or function, and any combination of arithmetic operators. Pass as many expression arguments as necessary.

Example

> select greatest(4, 7, 5);
+---------------------------+
| greatest(4,7,5)           |
+---------------------------+
| 7                         |
+---------------------------+

ifnull

Alias of nvl.

least

Returns the smallest value in a list of expressions. Returns null if all expressions are null.

least(expression1[, ..., expression_n])

Arguments

• expression1, expression_n: Expressions to compare and return the smallest value. Can be a constant, column, or function, and any combination of arithmetic operators. Pass as many expression arguments as necessary.

Example

> select least(4, 7, 5);
+---------------------------+
| least(4,7,5)              |
+---------------------------+
| 4                         |
+---------------------------+

nullif

Returns null if expression1 equals expression2; otherwise it returns expression1. This can be used to perform the inverse operation of coalesce.

nullif(expression1, expression2)

Arguments

• expression1: Expression to compare and return if equal to expression2. Can be a constant, column, or function, and any combination of operators.
• expression2: Expression to compare to expression1. Can be a constant, column, or function, and any combination of operators.

Example

> select nullif('datafusion', 'data');
+-----------------------------------------+
| nullif(Utf8("datafusion"),Utf8("data")) |
+-----------------------------------------+
| datafusion                              |
+-----------------------------------------+
> select nullif('datafusion', 'datafusion');
+-----------------------------------------------+
| nullif(Utf8("datafusion"),Utf8("datafusion")) |
+-----------------------------------------------+
|                                               |
+-----------------------------------------------+

nvl

Returns expression2 if expression1 is NULL otherwise it returns expression1.

nvl(expression1, expression2)

Arguments

• expression1: Expression to return if not null. Can be a constant, column, or function, and any combination of operators.
• expression2: Expression to return if expr1 is null. Can be a constant, column, or function, and any combination of operators.

Example

> select nvl(null, 'a');
+---------------------+
| nvl(NULL,Utf8("a")) |
+---------------------+
| a                   |
+---------------------+\
> select nvl('b', 'a');
+--------------------------+
| nvl(Utf8("b"),Utf8("a")) |
+--------------------------+
| b                        |
+--------------------------+

Aliases

• ifnull

nvl2

Returns expression2 if expression1 is not NULL; otherwise it returns expression3.

nvl2(expression1, expression2, expression3)

Arguments

• expression1: Expression to test for null. Can be a constant, column, or function, and any combination of operators.
• expression2: Expression to return if expr1 is not null. Can be a constant, column, or function, and any combination of operators.
• expression3: Expression to return if expr1 is null. Can be a constant, column, or function, and any combination of operators.

Example

> select nvl2(null, 'a', 'b');
+--------------------------------+
| nvl2(NULL,Utf8("a"),Utf8("b")) |
+--------------------------------+
| b                              |
+--------------------------------+
> select nvl2('data', 'a', 'b');
+----------------------------------------+
| nvl2(Utf8("data"),Utf8("a"),Utf8("b")) |
+----------------------------------------+
| a                                      |
+----------------------------------------+

String Functions

• ascii
• bit_length
• btrim
• char_length
• character_length
• chr
• concat
• concat_ws
• contains
• ends_with
• find_in_set
• initcap
• instr
• left
• length
• levenshtein
• lower
• lpad
• ltrim
• octet_length
• position
• repeat
• replace
• reverse
• right
• rpad
• rtrim
• split_part
• starts_with
• strpos
• substr
• substr_index
• substring
• substring_index
• to_hex
• translate
• trim
• upper
• uuid

ascii

Returns the Unicode character code of the first character in a string.

ascii(str)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select ascii('abc');
+--------------------+
| ascii(Utf8("abc")) |
+--------------------+
| 97                 |
+--------------------+
> select ascii('🚀');
+-------------------+
| ascii(Utf8("🚀")) |
+-------------------+
| 128640            |
+-------------------+

Related functions:

• chr

bit_length

Returns the bit length of a string.

bit_length(str)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select bit_length('datafusion');
+--------------------------------+
| bit_length(Utf8("datafusion")) |
+--------------------------------+
| 80                             |
+--------------------------------+

Related functions:

• length
• octet_length

btrim

Trims the specified trim string from the start and end of a string. If no trim string is provided, all whitespace is removed from the start and end of the input string.

btrim(str[, trim_str])

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• trim_str: String expression to operate on. Can be a constant, column, or function, and any combination of operators. Default is whitespace characters.

Example

> select btrim('__datafusion____', '_');
+-------------------------------------------+
| btrim(Utf8("__datafusion____"),Utf8("_")) |
+-------------------------------------------+
| datafusion                                |
+-------------------------------------------+

Alternative Syntax

trim(BOTH trim_str FROM str)

trim(trim_str FROM str)

Aliases

• trim

Related functions:

• ltrim
• rtrim

char_length

Alias of character_length.

character_length

Returns the number of characters in a string.

character_length(str)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select character_length('Ångström');
+------------------------------------+
| character_length(Utf8("Ångström")) |
+------------------------------------+
| 8                                  |
+------------------------------------+

Aliases

• length
• char_length

Related functions:

• bit_length
• octet_length

chr

Returns the character with the specified ASCII or Unicode code value.

chr(expression)

Arguments

• expression: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select chr(128640);
+--------------------+
| chr(Int64(128640)) |
+--------------------+
| 🚀                 |
+--------------------+

Related functions:

• ascii

concat

Concatenates multiple strings together.

concat(str[, ..., str_n])

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• str_n: Subsequent string expressions to concatenate.

Example

> select concat('data', 'f', 'us', 'ion');
+-------------------------------------------------------+
| concat(Utf8("data"),Utf8("f"),Utf8("us"),Utf8("ion")) |
+-------------------------------------------------------+
| datafusion                                            |
+-------------------------------------------------------+

Related functions:

• concat_ws

concat_ws

Concatenates multiple strings together with a specified separator.

concat_ws(separator, str[, ..., str_n])

Arguments

• separator: Separator to insert between concatenated strings.
• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• str_n: Subsequent string expressions to concatenate.

Example

> select concat_ws('_', 'data', 'fusion');
+--------------------------------------------------+
| concat_ws(Utf8("_"),Utf8("data"),Utf8("fusion")) |
+--------------------------------------------------+
| data_fusion                                      |
+--------------------------------------------------+

Related functions:

• concat

contains

Return true if search_str is found within string (case-sensitive).

contains(str, search_str)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• search_str: The string to search for in str.

Example

> select contains('the quick brown fox', 'row');
+---------------------------------------------------+
| contains(Utf8("the quick brown fox"),Utf8("row")) |
+---------------------------------------------------+
| true                                              |
+---------------------------------------------------+

ends_with

Tests if a string ends with a substring.

ends_with(str, substr)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• substr: Substring to test for.

Example

>  select ends_with('datafusion', 'soin');
+--------------------------------------------+
| ends_with(Utf8("datafusion"),Utf8("soin")) |
+--------------------------------------------+
| false                                      |
+--------------------------------------------+
> select ends_with('datafusion', 'sion');
+--------------------------------------------+
| ends_with(Utf8("datafusion"),Utf8("sion")) |
+--------------------------------------------+
| true                                       |
+--------------------------------------------+

find_in_set

Returns a value in the range of 1 to N if the string str is in the string list strlist consisting of N substrings.

find_in_set(str, strlist)

Arguments

• str: String expression to find in strlist.
• strlist: A string list is a string composed of substrings separated by , characters.

Example

> select find_in_set('b', 'a,b,c,d');
+----------------------------------------+
| find_in_set(Utf8("b"),Utf8("a,b,c,d")) |
+----------------------------------------+
| 2                                      |
+----------------------------------------+

initcap

Capitalizes the first character in each word in the input string. Words are delimited by non-alphanumeric characters.

initcap(str)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select initcap('apache datafusion');
+------------------------------------+
| initcap(Utf8("apache datafusion")) |
+------------------------------------+
| Apache Datafusion                  |
+------------------------------------+

Related functions:

• lower
• upper

instr

Alias of strpos.

left

Returns a specified number of characters from the left side of a string.

left(str, n)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• n: Number of characters to return.

Example

> select left('datafusion', 4);
+-----------------------------------+
| left(Utf8("datafusion"),Int64(4)) |
+-----------------------------------+
| data                              |
+-----------------------------------+

Related functions:

• right

length

Alias of character_length.

levenshtein

Returns the Levenshtein distance between the two given strings.

levenshtein(str1, str2)

Arguments

• str1: String expression to compute Levenshtein distance with str2.
• str2: String expression to compute Levenshtein distance with str1.

Example

> select levenshtein('kitten', 'sitting');
+---------------------------------------------+
| levenshtein(Utf8("kitten"),Utf8("sitting")) |
+---------------------------------------------+
| 3                                           |
+---------------------------------------------+

lower

Converts a string to lower-case.

lower(str)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select lower('Ångström');
+-------------------------+
| lower(Utf8("Ångström")) |
+-------------------------+
| ångström                |
+-------------------------+

Related functions:

• initcap
• upper

lpad

Pads the left side of a string with another string to a specified string length.

lpad(str, n[, padding_str])

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• n: String length to pad to.
• padding_str: Optional string expression to pad with. Can be a constant, column, or function, and any combination of string operators. Default is a space.

Example

> select lpad('Dolly', 10, 'hello');
+---------------------------------------------+
| lpad(Utf8("Dolly"),Int64(10),Utf8("hello")) |
+---------------------------------------------+
| helloDolly                                  |
+---------------------------------------------+

Related functions:

• rpad

ltrim

Trims the specified trim string from the beginning of a string. If no trim string is provided, all whitespace is removed from the start of the input string.

ltrim(str[, trim_str])

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• trim_str: String expression to trim from the beginning of the input string. Can be a constant, column, or function, and any combination of arithmetic operators. Default is whitespace characters.

Example

> select ltrim('  datafusion  ');
+-------------------------------+
| ltrim(Utf8("  datafusion  ")) |
+-------------------------------+
| datafusion                    |
+-------------------------------+
> select ltrim('___datafusion___', '_');
+-------------------------------------------+
| ltrim(Utf8("___datafusion___"),Utf8("_")) |
+-------------------------------------------+
| datafusion___                             |
+-------------------------------------------+

Alternative Syntax

trim(LEADING trim_str FROM str)

Related functions:

• btrim
• rtrim

octet_length

Returns the length of a string in bytes.

octet_length(str)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select octet_length('Ångström');
+--------------------------------+
| octet_length(Utf8("Ångström")) |
+--------------------------------+
| 10                             |
+--------------------------------+

Related functions:

• bit_length
• length

position

Alias of strpos.

repeat

Returns a string with an input string repeated a specified number.

repeat(str, n)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• n: Number of times to repeat the input string.

Example

> select repeat('data', 3);
+-------------------------------+
| repeat(Utf8("data"),Int64(3)) |
+-------------------------------+
| datadatadata                  |
+-------------------------------+

replace

Replaces all occurrences of a specified substring in a string with a new substring.

replace(str, substr, replacement)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• substr: Substring expression to replace in the input string. Substring expression to operate on. Can be a constant, column, or function, and any combination of operators.
• replacement: Replacement substring expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select replace('ABabbaBA', 'ab', 'cd');
+-------------------------------------------------+
| replace(Utf8("ABabbaBA"),Utf8("ab"),Utf8("cd")) |
+-------------------------------------------------+
| ABcdbaBA                                        |
+-------------------------------------------------+

reverse

Reverses the character order of a string.

reverse(str)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select reverse('datafusion');
+-----------------------------+
| reverse(Utf8("datafusion")) |
+-----------------------------+
| noisufatad                  |
+-----------------------------+

right

Returns a specified number of characters from the right side of a string.

right(str, n)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• n: Number of characters to return.

Example

> select right('datafusion', 6);
+------------------------------------+
| right(Utf8("datafusion"),Int64(6)) |
+------------------------------------+
| fusion                             |
+------------------------------------+

Related functions:

• left

rpad

Pads the right side of a string with another string to a specified string length.

rpad(str, n[, padding_str])

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• n: String length to pad to.
• padding_str: String expression to pad with. Can be a constant, column, or function, and any combination of string operators. Default is a space.

Example

>  select rpad('datafusion', 20, '_-');
+-----------------------------------------------+
| rpad(Utf8("datafusion"),Int64(20),Utf8("_-")) |
+-----------------------------------------------+
| datafusion_-_-_-_-_-                          |
+-----------------------------------------------+

Related functions:

• lpad

rtrim

Trims the specified trim string from the end of a string. If no trim string is provided, all whitespace is removed from the end of the input string.

rtrim(str[, trim_str])

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• trim_str: String expression to trim from the end of the input string. Can be a constant, column, or function, and any combination of arithmetic operators. Default is whitespace characters.

Example

> select rtrim('  datafusion  ');
+-------------------------------+
| rtrim(Utf8("  datafusion  ")) |
+-------------------------------+
|   datafusion                  |
+-------------------------------+
> select rtrim('___datafusion___', '_');
+-------------------------------------------+
| rtrim(Utf8("___datafusion___"),Utf8("_")) |
+-------------------------------------------+
| ___datafusion                             |
+-------------------------------------------+

Alternative Syntax

trim(TRAILING trim_str FROM str)

Related functions:

• btrim
• ltrim

split_part

Splits a string based on a specified delimiter and returns the substring in the specified position.

split_part(str, delimiter, pos)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• delimiter: String or character to split on.
• pos: Position of the part to return.

Example

> select split_part('1.2.3.4.5', '.', 3);
+--------------------------------------------------+
| split_part(Utf8("1.2.3.4.5"),Utf8("."),Int64(3)) |
+--------------------------------------------------+
| 3                                                |
+--------------------------------------------------+

starts_with

Tests if a string starts with a substring.

starts_with(str, substr)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• substr: Substring to test for.

Example

> select starts_with('datafusion','data');
+----------------------------------------------+
| starts_with(Utf8("datafusion"),Utf8("data")) |
+----------------------------------------------+
| true                                         |
+----------------------------------------------+

strpos

Returns the starting position of a specified substring in a string. Positions begin at 1. If the substring does not exist in the string, the function returns 0.

strpos(str, substr)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• substr: Substring expression to search for.

Example

> select strpos('datafusion', 'fus');
+----------------------------------------+
| strpos(Utf8("datafusion"),Utf8("fus")) |
+----------------------------------------+
| 5                                      |
+----------------------------------------+

Alternative Syntax

position(substr in origstr)

Aliases

• instr
• position

substr

Extracts a substring of a specified number of characters from a specific starting position in a string.

substr(str, start_pos[, length])

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• start_pos: Character position to start the substring at. The first character in the string has a position of 1.
• length: Number of characters to extract. If not specified, returns the rest of the string after the start position.

Example

> select substr('datafusion', 5, 3);
+----------------------------------------------+
| substr(Utf8("datafusion"),Int64(5),Int64(3)) |
+----------------------------------------------+
| fus                                          |
+----------------------------------------------+

Alternative Syntax

substring(str from start_pos for length)

Aliases

• substring

substr_index

Returns the substring from str before count occurrences of the delimiter delim. If count is positive, everything to the left of the final delimiter (counting from the left) is returned. If count is negative, everything to the right of the final delimiter (counting from the right) is returned.

substr_index(str, delim, count)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• delim: The string to find in str to split str.
• count: The number of times to search for the delimiter. Can be either a positive or negative number.

Example

> select substr_index('www.apache.org', '.', 1);
+---------------------------------------------------------+
| substr_index(Utf8("www.apache.org"),Utf8("."),Int64(1)) |
+---------------------------------------------------------+
| www                                                     |
+---------------------------------------------------------+
> select substr_index('www.apache.org', '.', -1);
+----------------------------------------------------------+
| substr_index(Utf8("www.apache.org"),Utf8("."),Int64(-1)) |
+----------------------------------------------------------+
| org                                                      |
+----------------------------------------------------------+

Aliases

• substring_index

substring

Alias of substr.

substring_index

Alias of substr_index.

to_hex

Converts an integer to a hexadecimal string.

to_hex(int)

Arguments

• int: Integer expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select to_hex(12345689);
+-------------------------+
| to_hex(Int64(12345689)) |
+-------------------------+
| bc6159                  |
+-------------------------+

translate

Translates characters in a string to specified translation characters.

translate(str, chars, translation)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• chars: Characters to translate.
• translation: Translation characters. Translation characters replace only characters at the same position in the chars string.

Example

> select translate('twice', 'wic', 'her');
+--------------------------------------------------+
| translate(Utf8("twice"),Utf8("wic"),Utf8("her")) |
+--------------------------------------------------+
| there                                            |
+--------------------------------------------------+

trim

Alias of btrim.

upper

Converts a string to upper-case.

upper(str)

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select upper('dataFusion');
+---------------------------+
| upper(Utf8("dataFusion")) |
+---------------------------+
| DATAFUSION                |
+---------------------------+

Related functions:

• initcap
• lower

uuid

Returns UUID v4 string value which is unique per row.

uuid()

Example

> select uuid();
+--------------------------------------+
| uuid()                               |
+--------------------------------------+
| 6ec17ef8-1934-41cc-8d59-d0c8f9eea1f0 |
+--------------------------------------+

Binary String Functions

• decode
• encode

decode

Decode binary data from textual representation in string.

decode(expression, format)

Arguments

• expression: Expression containing encoded string data
• format: Same arguments as encode

Related functions:

• encode

encode

Encode binary data into a textual representation.

encode(expression, format)

Arguments

• expression: Expression containing string or binary data
• format: Supported formats are: base64, hex

Related functions:

• decode

Regular Expression Functions

Apache DataFusion uses a PCRE-like regular expression syntax (minus support for several features including look-around and backreferences). The following regular expression functions are supported:

• regexp_count
• regexp_like
• regexp_match
• regexp_replace

regexp_count

Returns the number of matches that a regular expression has in a string.

regexp_count(str, regexp[, start, flags])

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• regexp: Regular expression to operate on. Can be a constant, column, or function, and any combination of operators.
• start: - start: Optional start position (the first position is 1) to search for the regular expression. Can be a constant, column, or function.
• flags: Optional regular expression flags that control the behavior of the regular expression. The following flags are supported:
  • i: case-insensitive: letters match both upper and lower case
  • m: multi-line mode: ^ and $ match begin/end of line
  • s: allow . to match \n
  • R: enables CRLF mode: when multi-line mode is enabled, \r\n is used
  • U: swap the meaning of x* and x*?

Example

> select regexp_count('abcAbAbc', 'abc', 2, 'i');
+---------------------------------------------------------------+
| regexp_count(Utf8("abcAbAbc"),Utf8("abc"),Int64(2),Utf8("i")) |
+---------------------------------------------------------------+
| 1                                                             |
+---------------------------------------------------------------+

regexp_like

Returns true if a regular expression has at least one match in a string, false otherwise.

regexp_like(str, regexp[, flags])

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• regexp: Regular expression to operate on. Can be a constant, column, or function, and any combination of operators.
• flags: Optional regular expression flags that control the behavior of the regular expression. The following flags are supported:
  • i: case-insensitive: letters match both upper and lower case
  • m: multi-line mode: ^ and $ match begin/end of line
  • s: allow . to match \n
  • R: enables CRLF mode: when multi-line mode is enabled, \r\n is used
  • U: swap the meaning of x* and x*?

Example

select regexp_like('Köln', '[a-zA-Z]ö[a-zA-Z]{2}');
+--------------------------------------------------------+
| regexp_like(Utf8("Köln"),Utf8("[a-zA-Z]ö[a-zA-Z]{2}")) |
+--------------------------------------------------------+
| true                                                   |
+--------------------------------------------------------+
SELECT regexp_like('aBc', '(b|d)', 'i');
+--------------------------------------------------+
| regexp_like(Utf8("aBc"),Utf8("(b|d)"),Utf8("i")) |
+--------------------------------------------------+
| true                                             |
+--------------------------------------------------+

Additional examples can be found here

regexp_match

Returns the first regular expression matches in a string.

regexp_match(str, regexp[, flags])

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• regexp: Regular expression to match against. Can be a constant, column, or function.
• flags: Optional regular expression flags that control the behavior of the regular expression. The following flags are supported:
  • i: case-insensitive: letters match both upper and lower case
  • m: multi-line mode: ^ and $ match begin/end of line
  • s: allow . to match \n
  • R: enables CRLF mode: when multi-line mode is enabled, \r\n is used
  • U: swap the meaning of x* and x*?

Example

            > select regexp_match('Köln', '[a-zA-Z]ö[a-zA-Z]{2}');
            +---------------------------------------------------------+
            | regexp_match(Utf8("Köln"),Utf8("[a-zA-Z]ö[a-zA-Z]{2}")) |
            +---------------------------------------------------------+
            | [Köln]                                                  |
            +---------------------------------------------------------+
            SELECT regexp_match('aBc', '(b|d)', 'i');
            +---------------------------------------------------+
            | regexp_match(Utf8("aBc"),Utf8("(b|d)"),Utf8("i")) |
            +---------------------------------------------------+
            | [B]                                               |
            +---------------------------------------------------+

Additional examples can be found here

regexp_replace

Replaces substrings in a string that match a regular expression.

regexp_replace(str, regexp, replacement[, flags])

Arguments

• str: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• regexp: Regular expression to match against. Can be a constant, column, or function.
• replacement: Replacement string expression to operate on. Can be a constant, column, or function, and any combination of operators.
• flags: Optional regular expression flags that control the behavior of the regular expression. The following flags are supported:
• g: (global) Search globally and don't return after the first match
• i: case-insensitive: letters match both upper and lower case
• m: multi-line mode: ^ and $ match begin/end of line
• s: allow . to match \n
• R: enables CRLF mode: when multi-line mode is enabled, \r\n is used
• U: swap the meaning of x* and x*?

Example

> select regexp_replace('foobarbaz', 'b(..)', 'X\\1Y', 'g');
+------------------------------------------------------------------------+
| regexp_replace(Utf8("foobarbaz"),Utf8("b(..)"),Utf8("X\1Y"),Utf8("g")) |
+------------------------------------------------------------------------+
| fooXarYXazY                                                            |
+------------------------------------------------------------------------+
SELECT regexp_replace('aBc', '(b|d)', 'Ab\\1a', 'i');
+-------------------------------------------------------------------+
| regexp_replace(Utf8("aBc"),Utf8("(b|d)"),Utf8("Ab\1a"),Utf8("i")) |
+-------------------------------------------------------------------+
| aAbBac                                                            |
+-------------------------------------------------------------------+

Additional examples can be found here

Time and Date Functions

• current_date
• current_time
• current_timestamp
• date_bin
• date_format
• date_part
• date_trunc
• datepart
• datetrunc
• from_unixtime
• make_date
• now
• to_char
• to_date
• to_local_time
• to_timestamp
• to_timestamp_micros
• to_timestamp_millis
• to_timestamp_nanos
• to_timestamp_seconds
• to_unixtime
• today

current_date

Returns the current UTC date.

The current_date() return value is determined at query time and will return the same date, no matter when in the query plan the function executes.

current_date()

Aliases

• today

current_time

Returns the current UTC time.

The current_time() return value is determined at query time and will return the same time, no matter when in the query plan the function executes.

current_time()

current_timestamp

Alias of now.

date_bin

Calculates time intervals and returns the start of the interval nearest to the specified timestamp. Use date_bin to downsample time series data by grouping rows into time-based "bins" or "windows" and applying an aggregate or selector function to each window.

For example, if you "bin" or "window" data into 15 minute intervals, an input timestamp of 2023-01-01T18:18:18Z will be updated to the start time of the 15 minute bin it is in: 2023-01-01T18:15:00Z.

date_bin(interval, expression, origin-timestamp)

Arguments

• interval: Bin interval.

• expression: Time expression to operate on. Can be a constant, column, or function.

• origin-timestamp: Optional. Starting point used to determine bin boundaries. If not specified defaults 1970-01-01T00:00:00Z (the UNIX epoch in UTC). The following intervals are supported:

  • nanoseconds
  • microseconds
  • milliseconds
  • seconds
  • minutes
  • hours
  • days
  • weeks
  • months
  • years
  • century

Example

-- Bin the timestamp into 1 day intervals
> SELECT date_bin(interval '1 day', time) as bin
FROM VALUES ('2023-01-01T18:18:18Z'), ('2023-01-03T19:00:03Z')  t(time);
+---------------------+
| bin                 |
+---------------------+
| 2023-01-01T00:00:00 |
| 2023-01-03T00:00:00 |
+---------------------+
2 row(s) fetched.

-- Bin the timestamp into 1 day intervals starting at 3AM on  2023-01-01
> SELECT date_bin(interval '1 day', time,  '2023-01-01T03:00:00') as bin
FROM VALUES ('2023-01-01T18:18:18Z'), ('2023-01-03T19:00:03Z')  t(time);
+---------------------+
| bin                 |
+---------------------+
| 2023-01-01T03:00:00 |
| 2023-01-03T03:00:00 |
+---------------------+
2 row(s) fetched.

date_format

Alias of to_char.

date_part

Returns the specified part of the date as an integer.

date_part(part, expression)

Arguments

• part: Part of the date to return. The following date parts are supported:

  • year
  • quarter (emits value in inclusive range [1, 4] based on which quartile of the year the date is in)
  • month
  • week (week of the year)
  • day (day of the month)
  • hour
  • minute
  • second
  • millisecond
  • microsecond
  • nanosecond
  • dow (day of the week)
  • doy (day of the year)
  • epoch (seconds since Unix epoch)

• expression: Time expression to operate on. Can be a constant, column, or function.

Alternative Syntax

extract(field FROM source)

Aliases

• datepart

date_trunc

Truncates a timestamp value to a specified precision.

date_trunc(precision, expression)

Arguments

• precision: Time precision to truncate to. The following precisions are supported:

  • year / YEAR
  • quarter / QUARTER
  • month / MONTH
  • week / WEEK
  • day / DAY
  • hour / HOUR
  • minute / MINUTE
  • second / SECOND

• expression: Time expression to operate on. Can be a constant, column, or function.

Aliases

• datetrunc

datepart

Alias of date_part.

datetrunc

Alias of date_trunc.

from_unixtime

Converts an integer to RFC3339 timestamp format (YYYY-MM-DDT00:00:00.000000000Z). Integers and unsigned integers are interpreted as nanoseconds since the unix epoch (1970-01-01T00:00:00Z) return the corresponding timestamp.

from_unixtime(expression[, timezone])

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.
• timezone: Optional timezone to use when converting the integer to a timestamp. If not provided, the default timezone is UTC.

Example

> select from_unixtime(1599572549, 'America/New_York');
+-----------------------------------------------------------+
| from_unixtime(Int64(1599572549),Utf8("America/New_York")) |
+-----------------------------------------------------------+
| 2020-09-08T09:42:29-04:00                                 |
+-----------------------------------------------------------+

make_date

Make a date from year/month/day component parts.

make_date(year, month, day)

Arguments

• year: Year to use when making the date. Can be a constant, column or function, and any combination of arithmetic operators.
• month: Month to use when making the date. Can be a constant, column or function, and any combination of arithmetic operators.
• day: Day to use when making the date. Can be a constant, column or function, and any combination of arithmetic operators.

Example

> select make_date(2023, 1, 31);
+-------------------------------------------+
| make_date(Int64(2023),Int64(1),Int64(31)) |
+-------------------------------------------+
| 2023-01-31                                |
+-------------------------------------------+
> select make_date('2023', '01', '31');
+-----------------------------------------------+
| make_date(Utf8("2023"),Utf8("01"),Utf8("31")) |
+-----------------------------------------------+
| 2023-01-31                                    |
+-----------------------------------------------+

Additional examples can be found here

now

Returns the current UTC timestamp.

The now() return value is determined at query time and will return the same timestamp, no matter when in the query plan the function executes.

now()

Aliases

• current_timestamp

to_char

Returns a string representation of a date, time, timestamp or duration based on a Chrono format. Unlike the PostgreSQL equivalent of this function numerical formatting is not supported.

to_char(expression, format)

Arguments

• expression: Expression to operate on. Can be a constant, column, or function that results in a date, time, timestamp or duration.
• format: A Chrono format string to use to convert the expression.
• day: Day to use when making the date. Can be a constant, column or function, and any combination of arithmetic operators.

Example

> select to_char('2023-03-01'::date, '%d-%m-%Y');
+----------------------------------------------+
| to_char(Utf8("2023-03-01"),Utf8("%d-%m-%Y")) |
+----------------------------------------------+
| 01-03-2023                                   |
+----------------------------------------------+

Additional examples can be found here

Aliases

• date_format

to_date

Converts a value to a date (YYYY-MM-DD). Supports strings, integer and double types as input. Strings are parsed as YYYY-MM-DD (e.g. '2023-07-20') if no Chrono formats are provided. Integers and doubles are interpreted as days since the unix epoch (1970-01-01T00:00:00Z). Returns the corresponding date.

Note: to_date returns Date32, which represents its values as the number of days since unix epoch(1970-01-01) stored as signed 32 bit value. The largest supported date value is 9999-12-31.

to_date('2017-05-31', '%Y-%m-%d')

Arguments

• expression: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• format_n: Optional Chrono format strings to use to parse the expression. Formats will be tried in the order they appear with the first successful one being returned. If none of the formats successfully parse the expression an error will be returned.

Example

> select to_date('2023-01-31');
+-------------------------------+
| to_date(Utf8("2023-01-31")) |
+-------------------------------+
| 2023-01-31                    |
+-------------------------------+
> select to_date('2023/01/31', '%Y-%m-%d', '%Y/%m/%d');
+---------------------------------------------------------------------+
| to_date(Utf8("2023/01/31"),Utf8("%Y-%m-%d"),Utf8("%Y/%m/%d")) |
+---------------------------------------------------------------------+
| 2023-01-31                                                          |
+---------------------------------------------------------------------+

Additional examples can be found here

to_local_time

Converts a timestamp with a timezone to a timestamp without a timezone (with no offset or timezone information). This function handles daylight saving time changes.

to_local_time(expression)

Arguments

• expression: Time expression to operate on. Can be a constant, column, or function.

Example

> SELECT to_local_time('2024-04-01T00:00:20Z'::timestamp);
+---------------------------------------------+
| to_local_time(Utf8("2024-04-01T00:00:20Z")) |
+---------------------------------------------+
| 2024-04-01T00:00:20                         |
+---------------------------------------------+

> SELECT to_local_time('2024-04-01T00:00:20Z'::timestamp AT TIME ZONE 'Europe/Brussels');
+---------------------------------------------+
| to_local_time(Utf8("2024-04-01T00:00:20Z")) |
+---------------------------------------------+
| 2024-04-01T00:00:20                         |
+---------------------------------------------+

> SELECT
  time,
  arrow_typeof(time) as type,
  to_local_time(time) as to_local_time,
  arrow_typeof(to_local_time(time)) as to_local_time_type
FROM (
  SELECT '2024-04-01T00:00:20Z'::timestamp AT TIME ZONE 'Europe/Brussels' AS time
);
+---------------------------+------------------------------------------------+---------------------+-----------------------------+
| time                      | type                                           | to_local_time       | to_local_time_type          |
+---------------------------+------------------------------------------------+---------------------+-----------------------------+
| 2024-04-01T00:00:20+02:00 | Timestamp(Nanosecond, Some("Europe/Brussels")) | 2024-04-01T00:00:20 | Timestamp(Nanosecond, None) |
+---------------------------+------------------------------------------------+---------------------+-----------------------------+

## combine `to_local_time()` with `date_bin()` to bin on boundaries in the timezone rather
## than UTC boundaries

> SELECT date_bin(interval '1 day', to_local_time('2024-04-01T00:00:20Z'::timestamp AT TIME ZONE 'Europe/Brussels')) AS date_bin;
+---------------------+
| date_bin            |
+---------------------+
| 2024-04-01T00:00:00 |
+---------------------+

> SELECT date_bin(interval '1 day', to_local_time('2024-04-01T00:00:20Z'::timestamp AT TIME ZONE 'Europe/Brussels')) AT TIME ZONE 'Europe/Brussels' AS date_bin_with_timezone;
+---------------------------+
| date_bin_with_timezone    |
+---------------------------+
| 2024-04-01T00:00:00+02:00 |
+---------------------------+

to_timestamp

Converts a value to a timestamp (YYYY-MM-DDT00:00:00Z). Supports strings, integer, unsigned integer, and double types as input. Strings are parsed as RFC3339 (e.g. '2023-07-20T05:44:00') if no [Chrono formats] are provided. Integers, unsigned integers, and doubles are interpreted as seconds since the unix epoch (1970-01-01T00:00:00Z). Returns the corresponding timestamp.

Note: to_timestamp returns Timestamp(Nanosecond). The supported range for integer input is between -9223372037 and 9223372036. Supported range for string input is between 1677-09-21T00:12:44.0 and 2262-04-11T23:47:16.0. Please use to_timestamp_seconds for the input outside of supported bounds.

to_timestamp(expression[, ..., format_n])

Arguments

• expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
• format_n: Optional Chrono format strings to use to parse the expression. Formats will be tried in the order they appear with the first successful one being returned. If none of the formats successfully parse the expression an error will be returned.

Example

> select to_timestamp('2023-01-31T09:26:56.123456789-05:00');
+-----------------------------------------------------------+
| to_timestamp(Utf8("2023-01-31T09:26:56.123456789-05:00")) |
+-----------------------------------------------------------+
| 2023-01-31T14:26:56.123456789                             |
+-----------------------------------------------------------+
> select to_timestamp('03:59:00.123456789 05-17-2023', '%c', '%+', '%H:%M:%S%.f %m-%d-%Y');
+--------------------------------------------------------------------------------------------------------+
| to_timestamp(Utf8("03:59:00.123456789 05-17-2023"),Utf8("%c"),Utf8("%+"),Utf8("%H:%M:%S%.f %m-%d-%Y")) |
+--------------------------------------------------------------------------------------------------------+
| 2023-05-17T03:59:00.123456789                                                                          |
+--------------------------------------------------------------------------------------------------------+

Additional examples can be found here

to_timestamp_micros

Converts a value to a timestamp (YYYY-MM-DDT00:00:00.000000Z). Supports strings, integer, and unsigned integer types as input. Strings are parsed as RFC3339 (e.g. '2023-07-20T05:44:00') if no Chrono formats are provided. Integers and unsigned integers are interpreted as microseconds since the unix epoch (1970-01-01T00:00:00Z) Returns the corresponding timestamp.

to_timestamp_micros(expression[, ..., format_n])

Arguments

• expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
• format_n: Optional Chrono format strings to use to parse the expression. Formats will be tried in the order they appear with the first successful one being returned. If none of the formats successfully parse the expression an error will be returned.

Example

> select to_timestamp_micros('2023-01-31T09:26:56.123456789-05:00');
+------------------------------------------------------------------+
| to_timestamp_micros(Utf8("2023-01-31T09:26:56.123456789-05:00")) |
+------------------------------------------------------------------+
| 2023-01-31T14:26:56.123456                                       |
+------------------------------------------------------------------+
> select to_timestamp_micros('03:59:00.123456789 05-17-2023', '%c', '%+', '%H:%M:%S%.f %m-%d-%Y');
+---------------------------------------------------------------------------------------------------------------+
| to_timestamp_micros(Utf8("03:59:00.123456789 05-17-2023"),Utf8("%c"),Utf8("%+"),Utf8("%H:%M:%S%.f %m-%d-%Y")) |
+---------------------------------------------------------------------------------------------------------------+
| 2023-05-17T03:59:00.123456                                                                                    |
+---------------------------------------------------------------------------------------------------------------+

Additional examples can be found here

to_timestamp_millis

Converts a value to a timestamp (YYYY-MM-DDT00:00:00.000Z). Supports strings, integer, and unsigned integer types as input. Strings are parsed as RFC3339 (e.g. '2023-07-20T05:44:00') if no Chrono formats are provided. Integers and unsigned integers are interpreted as milliseconds since the unix epoch (1970-01-01T00:00:00Z). Returns the corresponding timestamp.

to_timestamp_millis(expression[, ..., format_n])

Arguments

• expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
• format_n: Optional Chrono format strings to use to parse the expression. Formats will be tried in the order they appear with the first successful one being returned. If none of the formats successfully parse the expression an error will be returned.

Example

> select to_timestamp_millis('2023-01-31T09:26:56.123456789-05:00');
+------------------------------------------------------------------+
| to_timestamp_millis(Utf8("2023-01-31T09:26:56.123456789-05:00")) |
+------------------------------------------------------------------+
| 2023-01-31T14:26:56.123                                          |
+------------------------------------------------------------------+
> select to_timestamp_millis('03:59:00.123456789 05-17-2023', '%c', '%+', '%H:%M:%S%.f %m-%d-%Y');
+---------------------------------------------------------------------------------------------------------------+
| to_timestamp_millis(Utf8("03:59:00.123456789 05-17-2023"),Utf8("%c"),Utf8("%+"),Utf8("%H:%M:%S%.f %m-%d-%Y")) |
+---------------------------------------------------------------------------------------------------------------+
| 2023-05-17T03:59:00.123                                                                                       |
+---------------------------------------------------------------------------------------------------------------+

Additional examples can be found here

to_timestamp_nanos

Converts a value to a timestamp (YYYY-MM-DDT00:00:00.000000000Z). Supports strings, integer, and unsigned integer types as input. Strings are parsed as RFC3339 (e.g. '2023-07-20T05:44:00') if no Chrono formats are provided. Integers and unsigned integers are interpreted as nanoseconds since the unix epoch (1970-01-01T00:00:00Z). Returns the corresponding timestamp.

to_timestamp_nanos(expression[, ..., format_n])

Arguments

• expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
• format_n: Optional Chrono format strings to use to parse the expression. Formats will be tried in the order they appear with the first successful one being returned. If none of the formats successfully parse the expression an error will be returned.

Example

> select to_timestamp_nanos('2023-01-31T09:26:56.123456789-05:00');
+-----------------------------------------------------------------+
| to_timestamp_nanos(Utf8("2023-01-31T09:26:56.123456789-05:00")) |
+-----------------------------------------------------------------+
| 2023-01-31T14:26:56.123456789                                   |
+-----------------------------------------------------------------+
> select to_timestamp_nanos('03:59:00.123456789 05-17-2023', '%c', '%+', '%H:%M:%S%.f %m-%d-%Y');
+--------------------------------------------------------------------------------------------------------------+
| to_timestamp_nanos(Utf8("03:59:00.123456789 05-17-2023"),Utf8("%c"),Utf8("%+"),Utf8("%H:%M:%S%.f %m-%d-%Y")) |
+--------------------------------------------------------------------------------------------------------------+
| 2023-05-17T03:59:00.123456789                                                                                |
+---------------------------------------------------------------------------------------------------------------+

Additional examples can be found here

to_timestamp_seconds

Converts a value to a timestamp (YYYY-MM-DDT00:00:00.000Z). Supports strings, integer, and unsigned integer types as input. Strings are parsed as RFC3339 (e.g. '2023-07-20T05:44:00') if no Chrono formats are provided. Integers and unsigned integers are interpreted as seconds since the unix epoch (1970-01-01T00:00:00Z). Returns the corresponding timestamp.

to_timestamp_seconds(expression[, ..., format_n])

Arguments

• expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
• format_n: Optional Chrono format strings to use to parse the expression. Formats will be tried in the order they appear with the first successful one being returned. If none of the formats successfully parse the expression an error will be returned.

Example

> select to_timestamp_seconds('2023-01-31T09:26:56.123456789-05:00');
+-------------------------------------------------------------------+
| to_timestamp_seconds(Utf8("2023-01-31T09:26:56.123456789-05:00")) |
+-------------------------------------------------------------------+
| 2023-01-31T14:26:56                                               |
+-------------------------------------------------------------------+
> select to_timestamp_seconds('03:59:00.123456789 05-17-2023', '%c', '%+', '%H:%M:%S%.f %m-%d-%Y');
+----------------------------------------------------------------------------------------------------------------+
| to_timestamp_seconds(Utf8("03:59:00.123456789 05-17-2023"),Utf8("%c"),Utf8("%+"),Utf8("%H:%M:%S%.f %m-%d-%Y")) |
+----------------------------------------------------------------------------------------------------------------+
| 2023-05-17T03:59:00                                                                                            |
+----------------------------------------------------------------------------------------------------------------+

Additional examples can be found here

to_unixtime

Converts a value to seconds since the unix epoch (1970-01-01T00:00:00Z). Supports strings, dates, timestamps and double types as input. Strings are parsed as RFC3339 (e.g. '2023-07-20T05:44:00') if no Chrono formats are provided.

to_unixtime(expression[, ..., format_n])

Arguments

• expression: Expression to operate on. Can be a constant, column, or function, and any combination of arithmetic operators.
• format_n: Optional Chrono format strings to use to parse the expression. Formats will be tried in the order they appear with the first successful one being returned. If none of the formats successfully parse the expression an error will be returned.

Example

> select to_unixtime('2020-09-08T12:00:00+00:00');
+------------------------------------------------+
| to_unixtime(Utf8("2020-09-08T12:00:00+00:00")) |
+------------------------------------------------+
| 1599566400                                     |
+------------------------------------------------+
> select to_unixtime('01-14-2023 01:01:30+05:30', '%q', '%d-%m-%Y %H/%M/%S', '%+', '%m-%d-%Y %H:%M:%S%#z');
+-----------------------------------------------------------------------------------------------------------------------------+
| to_unixtime(Utf8("01-14-2023 01:01:30+05:30"),Utf8("%q"),Utf8("%d-%m-%Y %H/%M/%S"),Utf8("%+"),Utf8("%m-%d-%Y %H:%M:%S%#z")) |
+-----------------------------------------------------------------------------------------------------------------------------+
| 1673638290                                                                                                                  |
+-----------------------------------------------------------------------------------------------------------------------------+

today

Alias of current_date.

Array Functions

• array_any_value
• array_append
• array_cat
• array_concat
• array_contains
• array_dims
• array_distance
• array_distinct
• array_element
• array_empty
• array_except
• array_extract
• array_has
• array_has_all
• array_has_any
• array_indexof
• array_intersect
• array_join
• array_length
• array_ndims
• array_pop_back
• array_pop_front
• array_position
• array_positions
• array_prepend
• array_push_back
• array_push_front
• array_remove
• array_remove_all
• array_remove_n
• array_repeat
• array_replace
• array_replace_all
• array_replace_n
• array_resize
• array_reverse
• array_slice
• array_sort
• array_to_string
• array_union
• cardinality
• empty
• flatten
• generate_series
• list_any_value
• list_append
• list_cat
• list_concat
• list_contains
• list_dims
• list_distance
• list_distinct
• list_element
• list_empty
• list_except
• list_extract
• list_has
• list_has_all
• list_has_any
• list_indexof
• list_intersect
• list_join
• list_length
• list_ndims
• list_pop_back
• list_pop_front
• list_position
• list_positions
• list_prepend
• list_push_back
• list_push_front
• list_remove
• list_remove_all
• list_remove_n
• list_repeat
• list_replace
• list_replace_all
• list_replace_n
• list_resize
• list_reverse
• list_slice
• list_sort
• list_to_string
• list_union
• make_array
• make_list
• range
• string_to_array
• string_to_list

array_any_value

Returns the first non-null element in the array.

array_any_value(array)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select array_any_value([NULL, 1, 2, 3]);
+-------------------------------+
| array_any_value(List([NULL,1,2,3])) |
+-------------------------------------+
| 1                                   |
+-------------------------------------+

Aliases

• list_any_value

array_append

Appends an element to the end of an array.

array_append(array, element)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• element: Element to append to the array.

Example

> select array_append([1, 2, 3], 4);
+--------------------------------------+
| array_append(List([1,2,3]),Int64(4)) |
+--------------------------------------+
| [1, 2, 3, 4]                         |
+--------------------------------------+

Aliases

• list_append
• array_push_back
• list_push_back

array_cat

Alias of array_concat.

array_concat

Concatenates arrays.

array_concat(array[, ..., array_n])

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• array_n: Subsequent array column or literal array to concatenate.

Example

> select array_concat([1, 2], [3, 4], [5, 6]);
+---------------------------------------------------+
| array_concat(List([1,2]),List([3,4]),List([5,6])) |
+---------------------------------------------------+
| [1, 2, 3, 4, 5, 6]                                |
+---------------------------------------------------+

Aliases

• array_cat
• list_concat
• list_cat

array_contains

Alias of array_has.

array_dims

Returns an array of the array's dimensions.

array_dims(array)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select array_dims([[1, 2, 3], [4, 5, 6]]);
+---------------------------------+
| array_dims(List([1,2,3,4,5,6])) |
+---------------------------------+
| [2, 3]                          |
+---------------------------------+

Aliases

• list_dims

array_distance

Returns the Euclidean distance between two input arrays of equal length.

array_distance(array1, array2)

Arguments

• array1: Array expression. Can be a constant, column, or function, and any combination of array operators.
• array2: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select array_distance([1, 2], [1, 4]);
+------------------------------------+
| array_distance(List([1,2], [1,4])) |
+------------------------------------+
| 2.0                                |
+------------------------------------+

Aliases

• list_distance

array_distinct

Returns distinct values from the array after removing duplicates.

array_distinct(array)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select array_distinct([1, 3, 2, 3, 1, 2, 4]);
+---------------------------------+
| array_distinct(List([1,2,3,4])) |
+---------------------------------+
| [1, 2, 3, 4]                    |
+---------------------------------+

Aliases

• list_distinct

array_element

Extracts the element with the index n from the array.

array_element(array, index)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• index: Index to extract the element from the array.

Example

> select array_element([1, 2, 3, 4], 3);
+-----------------------------------------+
| array_element(List([1,2,3,4]),Int64(3)) |
+-----------------------------------------+
| 3                                       |
+-----------------------------------------+

Aliases

• array_extract
• list_element
• list_extract

array_empty

Alias of empty.

array_except

Returns an array of the elements that appear in the first array but not in the second.

array_except(array1, array2)

Arguments

• array1: Array expression. Can be a constant, column, or function, and any combination of array operators.
• array2: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select array_except([1, 2, 3, 4], [5, 6, 3, 4]);
+----------------------------------------------------+
| array_except([1, 2, 3, 4], [5, 6, 3, 4]);           |
+----------------------------------------------------+
| [1, 2]                                              |
+----------------------------------------------------+
> select array_except([1, 2, 3, 4], [3, 4, 5, 6]);
+----------------------------------------------------+
| array_except([1, 2, 3, 4], [3, 4, 5, 6]);           |
+----------------------------------------------------+
| [1, 2]                                              |
+----------------------------------------------------+

Aliases

• list_except

array_extract

Alias of array_element.

array_has

Returns true if the array contains the element.

array_has(array, element)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• element: Scalar or Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select array_has([1, 2, 3], 2);
+-----------------------------+
| array_has(List([1,2,3]), 2) |
+-----------------------------+
| true                        |
+-----------------------------+

Aliases

• list_has
• array_contains
• list_contains

array_has_all

Returns true if all elements of sub-array exist in array.

array_has_all(array, sub-array)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• sub-array: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select array_has_all([1, 2, 3, 4], [2, 3]);
+--------------------------------------------+
| array_has_all(List([1,2,3,4]), List([2,3])) |
+--------------------------------------------+
| true                                       |
+--------------------------------------------+

Aliases

• list_has_all

array_has_any

Returns true if any elements exist in both arrays.

array_has_any(array, sub-array)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• sub-array: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select array_has_any([1, 2, 3], [3, 4]);
+------------------------------------------+
| array_has_any(List([1,2,3]), List([3,4])) |
+------------------------------------------+
| true                                     |
+------------------------------------------+

Aliases

• list_has_any

array_indexof

Alias of array_position.

array_intersect

Returns an array of elements in the intersection of array1 and array2.

array_intersect(array1, array2)

Arguments

• array1: Array expression. Can be a constant, column, or function, and any combination of array operators.
• array2: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select array_intersect([1, 2, 3, 4], [5, 6, 3, 4]);
+----------------------------------------------------+
| array_intersect([1, 2, 3, 4], [5, 6, 3, 4]);       |
+----------------------------------------------------+
| [3, 4]                                             |
+----------------------------------------------------+
> select array_intersect([1, 2, 3, 4], [5, 6, 7, 8]);
+----------------------------------------------------+
| array_intersect([1, 2, 3, 4], [5, 6, 7, 8]);       |
+----------------------------------------------------+
| []                                                 |
+----------------------------------------------------+

Aliases

• list_intersect

array_join

Alias of array_to_string.

array_length

Returns the length of the array dimension.

array_length(array, dimension)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• dimension: Array dimension.

Example

> select array_length([1, 2, 3, 4, 5], 1);
+-------------------------------------------+
| array_length(List([1,2,3,4,5]), 1)        |
+-------------------------------------------+
| 5                                         |
+-------------------------------------------+

Aliases

• list_length

array_ndims

Returns the number of dimensions of the array.

array_ndims(array, element)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• element: Array element.

Example

> select array_ndims([[1, 2, 3], [4, 5, 6]]);
+----------------------------------+
| array_ndims(List([1,2,3,4,5,6])) |
+----------------------------------+
| 2                                |
+----------------------------------+

Aliases

• list_ndims

array_pop_back

Returns the array without the last element.

array_pop_back(array)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select array_pop_back([1, 2, 3]);
+-------------------------------+
| array_pop_back(List([1,2,3])) |
+-------------------------------+
| [1, 2]                        |
+-------------------------------+

Aliases

• list_pop_back

array_pop_front

Returns the array without the first element.

array_pop_front(array)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select array_pop_front([1, 2, 3]);
+-------------------------------+
| array_pop_front(List([1,2,3])) |
+-------------------------------+
| [2, 3]                        |
+-------------------------------+

Aliases

• list_pop_front

array_position

Returns the position of the first occurrence of the specified element in the array.

array_position(array, element)
array_position(array, element, index)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• element: Element to search for position in the array.
• index: Index at which to start searching.

Example

> select array_position([1, 2, 2, 3, 1, 4], 2);
+----------------------------------------------+
| array_position(List([1,2,2,3,1,4]),Int64(2)) |
+----------------------------------------------+
| 2                                            |
+----------------------------------------------+
> select array_position([1, 2, 2, 3, 1, 4], 2, 3);
+----------------------------------------------------+
| array_position(List([1,2,2,3,1,4]),Int64(2), Int64(3)) |
+----------------------------------------------------+
| 3                                                  |
+----------------------------------------------------+

Aliases

• list_position
• array_indexof
• list_indexof

array_positions

Searches for an element in the array, returns all occurrences.

array_positions(array, element)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• element: Element to search for position in the array.

Example

> select array_positions([1, 2, 2, 3, 1, 4], 2);
+-----------------------------------------------+
| array_positions(List([1,2,2,3,1,4]),Int64(2)) |
+-----------------------------------------------+
| [2, 3]                                        |
+-----------------------------------------------+

Aliases

• list_positions

array_prepend

Prepends an element to the beginning of an array.

array_prepend(element, array)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• element: Element to prepend to the array.

Example

> select array_prepend(1, [2, 3, 4]);
+---------------------------------------+
| array_prepend(Int64(1),List([2,3,4])) |
+---------------------------------------+
| [1, 2, 3, 4]                          |
+---------------------------------------+

Aliases

• list_prepend
• array_push_front
• list_push_front

array_push_back

Alias of array_append.

array_push_front

Alias of array_prepend.

array_remove

Removes the first element from the array equal to the given value.

array_remove(array, element)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• element: Element to be removed from the array.

Example

> select array_remove([1, 2, 2, 3, 2, 1, 4], 2);
+----------------------------------------------+
| array_remove(List([1,2,2,3,2,1,4]),Int64(2)) |
+----------------------------------------------+
| [1, 2, 3, 2, 1, 4]                           |
+----------------------------------------------+

Aliases

• list_remove

array_remove_all

Removes all elements from the array equal to the given value.

array_remove_all(array, element)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• element: Element to be removed from the array.

Example

> select array_remove_all([1, 2, 2, 3, 2, 1, 4], 2);
+--------------------------------------------------+
| array_remove_all(List([1,2,2,3,2,1,4]),Int64(2)) |
+--------------------------------------------------+
| [1, 3, 1, 4]                                     |
+--------------------------------------------------+

Aliases

• list_remove_all

array_remove_n

Removes the first max elements from the array equal to the given value.

array_remove_n(array, element, max))

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• element: Element to be removed from the array.
• max: Number of first occurrences to remove.

Example

> select array_remove_n([1, 2, 2, 3, 2, 1, 4], 2, 2);
+---------------------------------------------------------+
| array_remove_n(List([1,2,2,3,2,1,4]),Int64(2),Int64(2)) |
+---------------------------------------------------------+
| [1, 3, 2, 1, 4]                                         |
+---------------------------------------------------------+

Aliases

• list_remove_n

array_repeat

Returns an array containing element count times.

array_repeat(element, count)

Arguments

• element: Element expression. Can be a constant, column, or function, and any combination of array operators.
• count: Value of how many times to repeat the element.

Example

> select array_repeat(1, 3);
+---------------------------------+
| array_repeat(Int64(1),Int64(3)) |
+---------------------------------+
| [1, 1, 1]                       |
+---------------------------------+
> select array_repeat([1, 2], 2);
+------------------------------------+
| array_repeat(List([1,2]),Int64(2)) |
+------------------------------------+
| [[1, 2], [1, 2]]                   |
+------------------------------------+

Aliases

• list_repeat

array_replace

Replaces the first occurrence of the specified element with another specified element.

array_replace(array, from, to)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• from: Initial element.
• to: Final element.

Example

> select array_replace([1, 2, 2, 3, 2, 1, 4], 2, 5);
+--------------------------------------------------------+
| array_replace(List([1,2,2,3,2,1,4]),Int64(2),Int64(5)) |
+--------------------------------------------------------+
| [1, 5, 2, 3, 2, 1, 4]                                  |
+--------------------------------------------------------+

Aliases

• list_replace

array_replace_all

Replaces all occurrences of the specified element with another specified element.

array_replace_all(array, from, to)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• from: Initial element.
• to: Final element.

Example

> select array_replace_all([1, 2, 2, 3, 2, 1, 4], 2, 5);
+------------------------------------------------------------+
| array_replace_all(List([1,2,2,3,2,1,4]),Int64(2),Int64(5)) |
+------------------------------------------------------------+
| [1, 5, 5, 3, 5, 1, 4]                                      |
+------------------------------------------------------------+

Aliases

• list_replace_all

array_replace_n

Replaces the first max occurrences of the specified element with another specified element.

array_replace_n(array, from, to, max)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• from: Initial element.
• to: Final element.
• max: Number of first occurrences to replace.

Example

> select array_replace_n([1, 2, 2, 3, 2, 1, 4], 2, 5, 2);
+-------------------------------------------------------------------+
| array_replace_n(List([1,2,2,3,2,1,4]),Int64(2),Int64(5),Int64(2)) |
+-------------------------------------------------------------------+
| [1, 5, 5, 3, 2, 1, 4]                                             |
+-------------------------------------------------------------------+

Aliases

• list_replace_n

array_resize

Resizes the list to contain size elements. Initializes new elements with value or empty if value is not set.

array_resize(array, size, value)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• size: New size of given array.
• value: Defines new elements' value or empty if value is not set.

Example

> select array_resize([1, 2, 3], 5, 0);
+-------------------------------------+
| array_resize(List([1,2,3],5,0))     |
+-------------------------------------+
| [1, 2, 3, 0, 0]                     |
+-------------------------------------+

Aliases

• list_resize

array_reverse

Returns the array with the order of the elements reversed.

array_reverse(array)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select array_reverse([1, 2, 3, 4]);
+------------------------------------------------------------+
| array_reverse(List([1, 2, 3, 4]))                          |
+------------------------------------------------------------+
| [4, 3, 2, 1]                                               |
+------------------------------------------------------------+

Aliases

• list_reverse

array_slice

Returns a slice of the array based on 1-indexed start and end positions.

array_slice(array, begin, end)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• begin: Index of the first element. If negative, it counts backward from the end of the array.
• end: Index of the last element. If negative, it counts backward from the end of the array.
• stride: Stride of the array slice. The default is 1.

Example

> select array_slice([1, 2, 3, 4, 5, 6, 7, 8], 3, 6);
+--------------------------------------------------------+
| array_slice(List([1,2,3,4,5,6,7,8]),Int64(3),Int64(6)) |
+--------------------------------------------------------+
| [3, 4, 5, 6]                                           |
+--------------------------------------------------------+

Aliases

• list_slice

array_sort

Sort array.

array_sort(array, desc, nulls_first)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• desc: Whether to sort in descending order(ASC or DESC).
• nulls_first: Whether to sort nulls first(NULLS FIRST or NULLS LAST).

Example

> select array_sort([3, 1, 2]);
+-----------------------------+
| array_sort(List([3,1,2]))   |
+-----------------------------+
| [1, 2, 3]                   |
+-----------------------------+

Aliases

• list_sort

array_to_string

Converts each element to its text representation.

array_to_string(array, delimiter[, null_string])

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.
• delimiter: Array element separator.
• null_string: Optional. String to replace null values in the array. If not provided, nulls will be handled by default behavior.

Example

> select array_to_string([[1, 2, 3, 4], [5, 6, 7, 8]], ',');
+----------------------------------------------------+
| array_to_string(List([1,2,3,4,5,6,7,8]),Utf8(",")) |
+----------------------------------------------------+
| 1,2,3,4,5,6,7,8                                    |
+----------------------------------------------------+

Aliases

• list_to_string
• array_join
• list_join

array_union

Returns an array of elements that are present in both arrays (all elements from both arrays) with out duplicates.

array_union(array1, array2)

Arguments

• array1: Array expression. Can be a constant, column, or function, and any combination of array operators.
• array2: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select array_union([1, 2, 3, 4], [5, 6, 3, 4]);
+----------------------------------------------------+
| array_union([1, 2, 3, 4], [5, 6, 3, 4]);           |
+----------------------------------------------------+
| [1, 2, 3, 4, 5, 6]                                 |
+----------------------------------------------------+
> select array_union([1, 2, 3, 4], [5, 6, 7, 8]);
+----------------------------------------------------+
| array_union([1, 2, 3, 4], [5, 6, 7, 8]);           |
+----------------------------------------------------+
| [1, 2, 3, 4, 5, 6, 7, 8]                           |
+----------------------------------------------------+

Aliases

• list_union

cardinality

Returns the total number of elements in the array.

cardinality(array)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select cardinality([[1, 2, 3, 4], [5, 6, 7, 8]]);
+--------------------------------------+
| cardinality(List([1,2,3,4,5,6,7,8])) |
+--------------------------------------+
| 8                                    |
+--------------------------------------+

empty

Returns 1 for an empty array or 0 for a non-empty array.

empty(array)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select empty([1]);
+------------------+
| empty(List([1])) |
+------------------+
| 0                |
+------------------+

Aliases

• array_empty
• list_empty

flatten

Converts an array of arrays to a flat array.

• Applies to any depth of nested arrays
• Does not change arrays that are already flat

The flattened array contains all the elements from all source arrays.

flatten(array)

Arguments

• array: Array expression. Can be a constant, column, or function, and any combination of array operators.

Example

> select flatten([[1, 2], [3, 4]]);
+------------------------------+
| flatten(List([1,2], [3,4]))  |
+------------------------------+
| [1, 2, 3, 4]                 |
+------------------------------+

generate_series

Similar to the range function, but it includes the upper bound.

generate_series(start, stop, step)

Arguments

• start: Start of the series. Ints, timestamps, dates or string types that can be coerced to Date32 are supported.
• end: End of the series (included). Type must be the same as start.
• step: Increase by step (can not be 0). Steps less than a day are supported only for timestamp ranges.

Example

> select generate_series(1,3);
+------------------------------------+
| generate_series(Int64(1),Int64(3)) |
+------------------------------------+
| [1, 2, 3]                          |
+------------------------------------+

list_any_value

Alias of array_any_value.

list_append

Alias of array_append.

list_cat

Alias of array_concat.

list_concat

Alias of array_concat.

list_contains

Alias of array_has.

list_dims

Alias of array_dims.

list_distance

Alias of array_distance.

list_distinct

Alias of array_distinct.

list_element

Alias of array_element.

list_empty

Alias of empty.

list_except

Alias of array_except.

list_extract

Alias of array_element.

list_has

Alias of array_has.

list_has_all

Alias of array_has_all.

list_has_any

Alias of array_has_any.

list_indexof

Alias of array_position.

list_intersect

Alias of array_intersect.

list_join

Alias of array_to_string.

list_length

Alias of array_length.

list_ndims

Alias of array_ndims.

list_pop_back

Alias of array_pop_back.

list_pop_front

Alias of array_pop_front.

list_position

Alias of array_position.

list_positions

Alias of array_positions.

list_prepend

Alias of array_prepend.

list_push_back

Alias of array_append.

list_push_front

Alias of array_prepend.

list_remove

Alias of array_remove.

list_remove_all

Alias of array_remove_all.

list_remove_n

Alias of array_remove_n.

list_repeat

Alias of array_repeat.

list_replace

Alias of array_replace.

list_replace_all

Alias of array_replace_all.

list_replace_n

Alias of array_replace_n.

list_resize

Alias of array_resize.

list_reverse

Alias of array_reverse.

list_slice

Alias of array_slice.

list_sort

Alias of array_sort.

list_to_string

Alias of array_to_string.

list_union

Alias of array_union.

make_array

Returns an array using the specified input expressions.

make_array(expression1[, ..., expression_n])

Arguments

• expression_n: Expression to include in the output array. Can be a constant, column, or function, and any combination of arithmetic or string operators.

Example

> select make_array(1, 2, 3, 4, 5);
+----------------------------------------------------------+
| make_array(Int64(1),Int64(2),Int64(3),Int64(4),Int64(5)) |
+----------------------------------------------------------+
| [1, 2, 3, 4, 5]                                          |
+----------------------------------------------------------+

Aliases

• make_list

make_list

Alias of make_array.

range

Returns an Arrow array between start and stop with step. The range start..end contains all values with start <= x < end. It is empty if start >= end. Step cannot be 0.

range(start, stop, step)

Arguments

• start: Start of the range. Ints, timestamps, dates or string types that can be coerced to Date32 are supported.
• end: End of the range (not included). Type must be the same as start.
• step: Increase by step (cannot be 0). Steps less than a day are supported only for timestamp ranges.

Example

> select range(2, 10, 3);
+-----------------------------------+
| range(Int64(2),Int64(10),Int64(3))|
+-----------------------------------+
| [2, 5, 8]                         |
+-----------------------------------+

> select range(DATE '1992-09-01', DATE '1993-03-01', INTERVAL '1' MONTH);
+--------------------------------------------------------------+
| range(DATE '1992-09-01', DATE '1993-03-01', INTERVAL '1' MONTH) |
+--------------------------------------------------------------+
| [1992-09-01, 1992-10-01, 1992-11-01, 1992-12-01, 1993-01-01, 1993-02-01] |
+--------------------------------------------------------------+

string_to_array

Splits a string into an array of substrings based on a delimiter. Any substrings matching the optional null_str argument are replaced with NULL.

string_to_array(str, delimiter[, null_str])

Arguments

• str: String expression to split.
• delimiter: Delimiter string to split on.
• null_str: Substring values to be replaced with NULL.

Example

> select string_to_array('abc##def', '##');
+-----------------------------------+
| string_to_array(Utf8('abc##def'))  |
+-----------------------------------+
| ['abc', 'def']                    |
+-----------------------------------+
> select string_to_array('abc def', ' ', 'def');
+---------------------------------------------+
| string_to_array(Utf8('abc def'), Utf8(' '), Utf8('def')) |
+---------------------------------------------+
| ['abc', NULL]                               |
+---------------------------------------------+

Aliases

• string_to_list

string_to_list

Alias of string_to_array.

Struct Functions

• named_struct
• row
• struct

named_struct

Returns an Arrow struct using the specified name and input expressions pairs.

named_struct(expression1_name, expression1_input[, ..., expression_n_name, expression_n_input])

Arguments

• expression_n_name: Name of the column field. Must be a constant string.
• expression_n_input: Expression to include in the output struct. Can be a constant, column, or function, and any combination of arithmetic or string operators.

Example

For example, this query converts two columns a and b to a single column with a struct type of fields field_a and field_b:

> select * from t;
+---+---+
| a | b |
+---+---+
| 1 | 2 |
| 3 | 4 |
+---+---+
> select named_struct('field_a', a, 'field_b', b) from t;
+-------------------------------------------------------+
| named_struct(Utf8("field_a"),t.a,Utf8("field_b"),t.b) |
+-------------------------------------------------------+
| {field_a: 1, field_b: 2}                              |
| {field_a: 3, field_b: 4}                              |
+-------------------------------------------------------+

row

Alias of struct.

struct

Returns an Arrow struct using the specified input expressions optionally named. Fields in the returned struct use the optional name or the cN naming convention. For example: c0, c1, c2, etc.

struct(expression1[, ..., expression_n])

Arguments

• expression1, expression_n: Expression to include in the output struct. Can be a constant, column, or function, any combination of arithmetic or string operators.

Example

For example, this query converts two columns a and b to a single column with a struct type of fields field_a and c1:

> select * from t;
+---+---+
| a | b |
+---+---+
| 1 | 2 |
| 3 | 4 |
+---+---+

-- use default names `c0`, `c1`
> select struct(a, b) from t;
+-----------------+
| struct(t.a,t.b) |
+-----------------+
| {c0: 1, c1: 2}  |
| {c0: 3, c1: 4}  |
+-----------------+

-- name the first field `field_a`
select struct(a as field_a, b) from t;
+--------------------------------------------------+
| named_struct(Utf8("field_a"),t.a,Utf8("c1"),t.b) |
+--------------------------------------------------+
| {field_a: 1, c1: 2}                              |
| {field_a: 3, c1: 4}                              |
+--------------------------------------------------+

Aliases

• row

Map Functions

• element_at
• map
• map_extract
• map_keys
• map_values

element_at

Alias of map_extract.

map

Returns an Arrow map with the specified key-value pairs.

The make_map function creates a map from two lists: one for keys and one for values. Each key must be unique and non-null.

map(key, value)
map(key: value)
make_map(['key1', 'key2'], ['value1', 'value2'])

Arguments

• key: For map: Expression to be used for key. Can be a constant, column, function, or any combination of arithmetic or string operators. For make_map: The list of keys to be used in the map. Each key must be unique and non-null.
• value: For map: Expression to be used for value. Can be a constant, column, function, or any combination of arithmetic or string operators. For make_map: The list of values to be mapped to the corresponding keys.

Example

-- Using map function
SELECT MAP('type', 'test');
----
{type: test}

SELECT MAP(['POST', 'HEAD', 'PATCH'], [41, 33, null]);
----
{POST: 41, HEAD: 33, PATCH: NULL}

SELECT MAP([[1,2], [3,4]], ['a', 'b']);
----
{[1, 2]: a, [3, 4]: b}

SELECT MAP { 'a': 1, 'b': 2 };
----
{a: 1, b: 2}

-- Using make_map function
SELECT MAKE_MAP(['POST', 'HEAD'], [41, 33]);
----
{POST: 41, HEAD: 33}

SELECT MAKE_MAP(['key1', 'key2'], ['value1', null]);
----
{key1: value1, key2: }

map_extract

Returns a list containing the value for the given key or an empty list if the key is not present in the map.

map_extract(map, key)

Arguments

• map: Map expression. Can be a constant, column, or function, and any combination of map operators.
• key: Key to extract from the map. Can be a constant, column, or function, any combination of arithmetic or string operators, or a named expression of the previously listed.

Example

SELECT map_extract(MAP {'a': 1, 'b': NULL, 'c': 3}, 'a');
----
[1]

SELECT map_extract(MAP {1: 'one', 2: 'two'}, 2);
----
['two']

SELECT map_extract(MAP {'x': 10, 'y': NULL, 'z': 30}, 'y');
----
[]

Aliases

• element_at

map_keys

Returns a list of all keys in the map.

map_keys(map)

Arguments

• map: Map expression. Can be a constant, column, or function, and any combination of map operators.

Example

SELECT map_keys(MAP {'a': 1, 'b': NULL, 'c': 3});
----
[a, b, c]

SELECT map_keys(map([100, 5], [42, 43]));
----
[100, 5]

map_values

Returns a list of all values in the map.

map_values(map)

Arguments

• map: Map expression. Can be a constant, column, or function, and any combination of map operators.

Example

SELECT map_values(MAP {'a': 1, 'b': NULL, 'c': 3});
----
[1, , 3]

SELECT map_values(map([100, 5], [42, 43]));
----
[42, 43]

Hashing Functions

• digest
• md5
• sha224
• sha256
• sha384
• sha512

digest

Computes the binary hash of an expression using the specified algorithm.

digest(expression, algorithm)

Arguments

• expression: String expression to operate on. Can be a constant, column, or function, and any combination of operators.
• algorithm: String expression specifying algorithm to use. Must be one of:
  • md5
  • sha224
  • sha256
  • sha384
  • sha512
  • blake2s
  • blake2b
  • blake3

Example

> select digest('foo', 'sha256');
+------------------------------------------+
| digest(Utf8("foo"), Utf8("sha256"))      |
+------------------------------------------+
| <binary_hash_result>                     |
+------------------------------------------+

md5

Computes an MD5 128-bit checksum for a string expression.

md5(expression)

Arguments

• expression: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select md5('foo');
+-------------------------------------+
| md5(Utf8("foo"))                    |
+-------------------------------------+
| <md5_checksum_result>               |
+-------------------------------------+

sha224

Computes the SHA-224 hash of a binary string.

sha224(expression)

Arguments

• expression: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select sha224('foo');
+------------------------------------------+
| sha224(Utf8("foo"))                      |
+------------------------------------------+
| <sha224_hash_result>                     |
+------------------------------------------+

sha256

Computes the SHA-256 hash of a binary string.

sha256(expression)

Arguments

• expression: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select sha256('foo');
+--------------------------------------+
| sha256(Utf8("foo"))                  |
+--------------------------------------+
| <sha256_hash_result>                 |
+--------------------------------------+

sha384

Computes the SHA-384 hash of a binary string.

sha384(expression)

Arguments

• expression: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select sha384('foo');
+-----------------------------------------+
| sha384(Utf8("foo"))                     |
+-----------------------------------------+
| <sha384_hash_result>                    |
+-----------------------------------------+

sha512

Computes the SHA-512 hash of a binary string.

sha512(expression)

Arguments

• expression: String expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> select sha512('foo');
+-------------------------------------------+
| sha512(Utf8("foo"))                       |
+-------------------------------------------+
| <sha512_hash_result>                      |
+-------------------------------------------+

Other Functions

• arrow_cast
• arrow_typeof
• get_field
• version

arrow_cast

Casts a value to a specific Arrow data type.

arrow_cast(expression, datatype)

Arguments

• expression: Expression to cast. The expression can be a constant, column, or function, and any combination of operators.
• datatype: Arrow data type name to cast to, as a string. The format is the same as that returned by [arrow_typeof]

Example

> select arrow_cast(-5, 'Int8') as a,
  arrow_cast('foo', 'Dictionary(Int32, Utf8)') as b,
  arrow_cast('bar', 'LargeUtf8') as c,
  arrow_cast('2023-01-02T12:53:02', 'Timestamp(Microsecond, Some("+08:00"))') as d
  ;
+----+-----+-----+---------------------------+
| a  | b   | c   | d                         |
+----+-----+-----+---------------------------+
| -5 | foo | bar | 2023-01-02T12:53:02+08:00 |
+----+-----+-----+---------------------------+

arrow_typeof

Returns the name of the underlying Arrow data type of the expression.

arrow_typeof(expression)

Arguments

• expression: Expression to evaluate. The expression can be a constant, column, or function, and any combination of operators.

Example

> select arrow_typeof('foo'), arrow_typeof(1);
+---------------------------+------------------------+
| arrow_typeof(Utf8("foo")) | arrow_typeof(Int64(1)) |
+---------------------------+------------------------+
| Utf8                      | Int64                  |
+---------------------------+------------------------+

get_field

Returns a field within a map or a struct with the given key. Note: most users invoke get_field indirectly via field access syntax such as my_struct_col['field_name'] which results in a call to get_field(my_struct_col, 'field_name').

get_field(expression1, expression2)

Arguments

• expression1: The map or struct to retrieve a field for.
• expression2: The field name in the map or struct to retrieve data for. Must evaluate to a string.

Example

> create table t (idx varchar, v varchar) as values ('data','fusion'), ('apache', 'arrow');
> select struct(idx, v) from t as c;
+-------------------------+
| struct(c.idx,c.v)       |
+-------------------------+
| {c0: data, c1: fusion}  |
| {c0: apache, c1: arrow} |
+-------------------------+
> select get_field((select struct(idx, v) from t), 'c0');
+-----------------------+
| struct(t.idx,t.v)[c0] |
+-----------------------+
| data                  |
| apache                |
+-----------------------+
> select get_field((select struct(idx, v) from t), 'c1');
+-----------------------+
| struct(t.idx,t.v)[c1] |
+-----------------------+
| fusion                |
| arrow                 |
+-----------------------+

version

Returns the version of DataFusion.

version()

Example

> select version();
+--------------------------------------------+
| version()                                  |
+--------------------------------------------+
| Apache DataFusion 42.0.0, aarch64 on macos |
+--------------------------------------------+

404: Not Found

Aggregate Functions

Aggregate functions operate on a set of values to compute a single result.

General Functions

• array_agg
• avg
• bit_and
• bit_or
• bit_xor
• bool_and
• bool_or
• count
• first_value
• grouping
• last_value
• max
• mean
• median
• min
• string_agg
• sum
• var
• var_pop
• var_population
• var_samp
• var_sample

array_agg

Returns an array created from the expression elements. If ordering is required, elements are inserted in the specified order.

array_agg(expression [ORDER BY expression])

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT array_agg(column_name ORDER BY other_column) FROM table_name;
+-----------------------------------------------+
| array_agg(column_name ORDER BY other_column)  |
+-----------------------------------------------+
| [element1, element2, element3]                |
+-----------------------------------------------+

avg

Returns the average of numeric values in the specified column.

avg(expression)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT avg(column_name) FROM table_name;
+---------------------------+
| avg(column_name)           |
+---------------------------+
| 42.75                      |
+---------------------------+

Aliases

• mean

bit_and

Computes the bitwise AND of all non-null input values.

bit_and(expression)

Arguments

• expression: Integer expression to operate on. Can be a constant, column, or function, and any combination of operators.

bit_or

Computes the bitwise OR of all non-null input values.

bit_or(expression)

Arguments

• expression: Integer expression to operate on. Can be a constant, column, or function, and any combination of operators.

bit_xor

Computes the bitwise exclusive OR of all non-null input values.

bit_xor(expression)

Arguments

• expression: Integer expression to operate on. Can be a constant, column, or function, and any combination of operators.

bool_and

Returns true if all non-null input values are true, otherwise false.

bool_and(expression)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT bool_and(column_name) FROM table_name;
+----------------------------+
| bool_and(column_name)       |
+----------------------------+
| true                        |
+----------------------------+

bool_or

Returns true if all non-null input values are true, otherwise false.

bool_and(expression)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT bool_and(column_name) FROM table_name;
+----------------------------+
| bool_and(column_name)       |
+----------------------------+
| true                        |
+----------------------------+

count

Returns the number of non-null values in the specified column. To include null values in the total count, use count(*).

count(expression)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT count(column_name) FROM table_name;
+-----------------------+
| count(column_name)     |
+-----------------------+
| 100                   |
+-----------------------+

> SELECT count(*) FROM table_name;
+------------------+
| count(*)         |
+------------------+
| 120              |
+------------------+

first_value

Returns the first element in an aggregation group according to the requested ordering. If no ordering is given, returns an arbitrary element from the group.

first_value(expression [ORDER BY expression])

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT first_value(column_name ORDER BY other_column) FROM table_name;
+-----------------------------------------------+
| first_value(column_name ORDER BY other_column)|
+-----------------------------------------------+
| first_element                                 |
+-----------------------------------------------+

grouping

Returns 1 if the data is aggregated across the specified column, or 0 if it is not aggregated in the result set.

grouping(expression)

Arguments

• expression: Expression to evaluate whether data is aggregated across the specified column. Can be a constant, column, or function.

Example

> SELECT column_name, GROUPING(column_name) AS group_column
  FROM table_name
  GROUP BY GROUPING SETS ((column_name), ());
+-------------+-------------+
| column_name | group_column |
+-------------+-------------+
| value1      | 0           |
| value2      | 0           |
| NULL        | 1           |
+-------------+-------------+

last_value

Returns the last element in an aggregation group according to the requested ordering. If no ordering is given, returns an arbitrary element from the group.

last_value(expression [ORDER BY expression])

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT last_value(column_name ORDER BY other_column) FROM table_name;
+-----------------------------------------------+
| last_value(column_name ORDER BY other_column) |
+-----------------------------------------------+
| last_element                                  |
+-----------------------------------------------+

max

Returns the maximum value in the specified column.

max(expression)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT max(column_name) FROM table_name;
+----------------------+
| max(column_name)      |
+----------------------+
| 150                  |
+----------------------+

mean

Alias of avg.

median

Returns the median value in the specified column.

median(expression)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT median(column_name) FROM table_name;
+----------------------+
| median(column_name)   |
+----------------------+
| 45.5                 |
+----------------------+

min

Returns the minimum value in the specified column.

min(expression)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT min(column_name) FROM table_name;
+----------------------+
| min(column_name)      |
+----------------------+
| 12                   |
+----------------------+

string_agg

Concatenates the values of string expressions and places separator values between them.

string_agg(expression, delimiter)

Arguments

• expression: The string expression to concatenate. Can be a column or any valid string expression.
• delimiter: A literal string used as a separator between the concatenated values.

Example

> SELECT string_agg(name, ', ') AS names_list
  FROM employee;
+--------------------------+
| names_list               |
+--------------------------+
| Alice, Bob, Charlie      |
+--------------------------+

sum

Returns the sum of all values in the specified column.

sum(expression)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT sum(column_name) FROM table_name;
+-----------------------+
| sum(column_name)       |
+-----------------------+
| 12345                 |
+-----------------------+

var

Returns the statistical sample variance of a set of numbers.

var(expression)

Arguments

• expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

Aliases

• var_sample
• var_samp

var_pop

Returns the statistical population variance of a set of numbers.

var_pop(expression)

Arguments

• expression: Numeric expression to operate on. Can be a constant, column, or function, and any combination of operators.

Aliases

• var_population

var_population

Alias of var_pop.

var_samp

Alias of var.

var_sample

Alias of var.

Statistical Functions

• corr
• covar
• covar_pop
• covar_samp
• nth_value
• regr_avgx
• regr_avgy
• regr_count
• regr_intercept
• regr_r2
• regr_slope
• regr_sxx
• regr_sxy
• regr_syy
• stddev
• stddev_pop
• stddev_samp

corr

Returns the coefficient of correlation between two numeric values.

corr(expression1, expression2)

Arguments

• expression1: First expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression2: Second expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT corr(column1, column2) FROM table_name;
+--------------------------------+
| corr(column1, column2)         |
+--------------------------------+
| 0.85                           |
+--------------------------------+

covar

Alias of covar_samp.

covar_pop

Returns the sample covariance of a set of number pairs.

covar_samp(expression1, expression2)

Arguments

• expression1: First expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression2: Second expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT covar_samp(column1, column2) FROM table_name;
+-----------------------------------+
| covar_samp(column1, column2)      |
+-----------------------------------+
| 8.25                              |
+-----------------------------------+

covar_samp

Returns the sample covariance of a set of number pairs.

covar_samp(expression1, expression2)

Arguments

• expression1: First expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression2: Second expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT covar_samp(column1, column2) FROM table_name;
+-----------------------------------+
| covar_samp(column1, column2)      |
+-----------------------------------+
| 8.25                              |
+-----------------------------------+

Aliases

• covar

nth_value

Returns the nth value in a group of values.

nth_value(expression, n ORDER BY expression)

Arguments

• expression: The column or expression to retrieve the nth value from.
• n: The position (nth) of the value to retrieve, based on the ordering.

Example

> SELECT dept_id, salary, NTH_VALUE(salary, 2) OVER (PARTITION BY dept_id ORDER BY salary ASC) AS second_salary_by_dept
  FROM employee;
+---------+--------+-------------------------+
| dept_id | salary | second_salary_by_dept   |
+---------+--------+-------------------------+
| 1       | 30000  | NULL                    |
| 1       | 40000  | 40000                   |
| 1       | 50000  | 40000                   |
| 2       | 35000  | NULL                    |
| 2       | 45000  | 45000                   |
+---------+--------+-------------------------+

regr_avgx

Computes the average of the independent variable (input) expression_x for the non-null paired data points.

regr_avgx(expression_y, expression_x)

Arguments

• expression_y: Dependent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression_x: Independent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.

regr_avgy

Computes the average of the dependent variable (output) expression_y for the non-null paired data points.

regr_avgy(expression_y, expression_x)

Arguments

• expression_y: Dependent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression_x: Independent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.

regr_count

Counts the number of non-null paired data points.

regr_count(expression_y, expression_x)

Arguments

• expression_y: Dependent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression_x: Independent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.

regr_intercept

Computes the y-intercept of the linear regression line. For the equation (y = kx + b), this function returns b.

regr_intercept(expression_y, expression_x)

Arguments

• expression_y: Dependent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression_x: Independent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.

regr_r2

Computes the square of the correlation coefficient between the independent and dependent variables.

regr_r2(expression_y, expression_x)

Arguments

• expression_y: Dependent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression_x: Independent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.

regr_slope

Returns the slope of the linear regression line for non-null pairs in aggregate columns. Given input column Y and X: regr_slope(Y, X) returns the slope (k in Y = k*X + b) using minimal RSS fitting.

regr_slope(expression_y, expression_x)

Arguments

• expression_y: Dependent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression_x: Independent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.

regr_sxx

Computes the sum of squares of the independent variable.

regr_sxx(expression_y, expression_x)

Arguments

• expression_y: Dependent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression_x: Independent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.

regr_sxy

Computes the sum of products of paired data points.

regr_sxy(expression_y, expression_x)

Arguments

• expression_y: Dependent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression_x: Independent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.

regr_syy

Computes the sum of squares of the dependent variable.

regr_syy(expression_y, expression_x)

Arguments

• expression_y: Dependent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.
• expression_x: Independent variable expression to operate on. Can be a constant, column, or function, and any combination of operators.

stddev

Returns the standard deviation of a set of numbers.

stddev(expression)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT stddev(column_name) FROM table_name;
+----------------------+
| stddev(column_name)   |
+----------------------+
| 12.34                |
+----------------------+

Aliases

• stddev_samp

stddev_pop

Returns the population standard deviation of a set of numbers.

stddev_pop(expression)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT stddev_pop(column_name) FROM table_name;
+--------------------------+
| stddev_pop(column_name)   |
+--------------------------+
| 10.56                    |
+--------------------------+

stddev_samp

Alias of stddev.

Approximate Functions

• approx_distinct
• approx_median
• approx_percentile_cont
• approx_percentile_cont_with_weight

approx_distinct

Returns the approximate number of distinct input values calculated using the HyperLogLog algorithm.

approx_distinct(expression)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT approx_distinct(column_name) FROM table_name;
+-----------------------------------+
| approx_distinct(column_name)      |
+-----------------------------------+
| 42                                |
+-----------------------------------+

approx_median

Returns the approximate median (50th percentile) of input values. It is an alias of approx_percentile_cont(x, 0.5).

approx_median(expression)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.

Example

> SELECT approx_median(column_name) FROM table_name;
+-----------------------------------+
| approx_median(column_name)        |
+-----------------------------------+
| 23.5                              |
+-----------------------------------+

approx_percentile_cont

Returns the approximate percentile of input values using the t-digest algorithm.

approx_percentile_cont(expression, percentile, centroids)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.
• percentile: Percentile to compute. Must be a float value between 0 and 1 (inclusive).
• centroids: Number of centroids to use in the t-digest algorithm. Default is 100. A higher number results in more accurate approximation but requires more memory.

Example

> SELECT approx_percentile_cont(column_name, 0.75, 100) FROM table_name;
+-------------------------------------------------+
| approx_percentile_cont(column_name, 0.75, 100)  |
+-------------------------------------------------+
| 65.0                                            |
+-------------------------------------------------+

approx_percentile_cont_with_weight

Returns the weighted approximate percentile of input values using the t-digest algorithm.

approx_percentile_cont_with_weight(expression, weight, percentile)

Arguments

• expression: The expression to operate on. Can be a constant, column, or function, and any combination of operators.
• weight: Expression to use as weight. Can be a constant, column, or function, and any combination of arithmetic operators.
• percentile: Percentile to compute. Must be a float value between 0 and 1 (inclusive).

Example

> SELECT approx_percentile_cont_with_weight(column_name, weight_column, 0.90) FROM table_name;
+----------------------------------------------------------------------+
| approx_percentile_cont_with_weight(column_name, weight_column, 0.90) |
+----------------------------------------------------------------------+
| 78.5                                                                 |
+----------------------------------------------------------------------+

Window Functions

A window function performs a calculation across a set of table rows that are somehow related to the current row. This is comparable to the type of calculation that can be done with an aggregate function. However, window functions do not cause rows to become grouped into a single output row like non-window aggregate calls would. Instead, the rows retain their separate identities. Behind the scenes, the window function is able to access more than just the current row of the query result

Here is an example that shows how to compare each employee's salary with the average salary in his or her department:

SELECT depname, empno, salary, avg(salary) OVER (PARTITION BY depname) FROM empsalary;

+-----------+-------+--------+-------------------+
| depname   | empno | salary | avg               |
+-----------+-------+--------+-------------------+
| personnel | 2     | 3900   | 3700.0            |
| personnel | 5     | 3500   | 3700.0            |
| develop   | 8     | 6000   | 5020.0            |
| develop   | 10    | 5200   | 5020.0            |
| develop   | 11    | 5200   | 5020.0            |
| develop   | 9     | 4500   | 5020.0            |
| develop   | 7     | 4200   | 5020.0            |
| sales     | 1     | 5000   | 4866.666666666667 |
| sales     | 4     | 4800   | 4866.666666666667 |
| sales     | 3     | 4800   | 4866.666666666667 |
+-----------+-------+--------+-------------------+

A window function call always contains an OVER clause directly following the window function's name and argument(s). This is what syntactically distinguishes it from a normal function or non-window aggregate. The OVER clause determines exactly how the rows of the query are split up for processing by the window function. The PARTITION BY clause within OVER divides the rows into groups, or partitions, that share the same values of the PARTITION BY expression(s). For each row, the window function is computed across the rows that fall into the same partition as the current row. The previous example showed how to count the average of a column per partition.

You can also control the order in which rows are processed by window functions using ORDER BY within OVER. (The window ORDER BY does not even have to match the order in which the rows are output.) Here is an example:

SELECT depname, empno, salary,
       rank() OVER (PARTITION BY depname ORDER BY salary DESC)
FROM empsalary;

+-----------+-------+--------+--------+
| depname   | empno | salary | rank   |
+-----------+-------+--------+--------+
| personnel | 2     | 3900   | 1      |
| develop   | 8     | 6000   | 1      |
| develop   | 10    | 5200   | 2      |
| develop   | 11    | 5200   | 2      |
| develop   | 9     | 4500   | 4      |
| develop   | 7     | 4200   | 5      |
| sales     | 1     | 5000   | 1      |
| sales     | 4     | 4800   | 2      |
| personnel | 5     | 3500   | 2      |
| sales     | 3     | 4800   | 2      |
+-----------+-------+--------+--------+

There is another important concept associated with window functions: for each row, there is a set of rows within its partition called its window frame. Some window functions act only on the rows of the window frame, rather than of the whole partition. Here is an example of using window frames in queries:

SELECT depname, empno, salary,
    avg(salary) OVER(ORDER BY salary ASC ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING) AS avg,
    min(salary) OVER(ORDER BY empno ASC ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS cum_min
FROM empsalary
ORDER BY empno ASC;

+-----------+-------+--------+--------------------+---------+
| depname   | empno | salary | avg                | cum_min |
+-----------+-------+--------+--------------------+---------+
| sales     | 1     | 5000   | 5000.0             | 5000    |
| personnel | 2     | 3900   | 3866.6666666666665 | 3900    |
| sales     | 3     | 4800   | 4700.0             | 3900    |
| sales     | 4     | 4800   | 4866.666666666667  | 3900    |
| personnel | 5     | 3500   | 3700.0             | 3500    |
| develop   | 7     | 4200   | 4200.0             | 3500    |
| develop   | 8     | 6000   | 5600.0             | 3500    |
| develop   | 9     | 4500   | 4500.0             | 3500    |
| develop   | 10    | 5200   | 5133.333333333333  | 3500    |
| develop   | 11    | 5200   | 5466.666666666667  | 3500    |
+-----------+-------+--------+--------------------+---------+

When a query involves multiple window functions, it is possible to write out each one with a separate OVER clause, but this is duplicative and error-prone if the same windowing behavior is wanted for several functions. Instead, each windowing behavior can be named in a WINDOW clause and then referenced in OVER. For example:

SELECT sum(salary) OVER w, avg(salary) OVER w
FROM empsalary
WINDOW w AS (PARTITION BY depname ORDER BY salary DESC);

Syntax

The syntax for the OVER-clause is

function([expr])
  OVER(
    [PARTITION BY expr[, …]]
    [ORDER BY expr [ ASC | DESC ][, …]]
    [ frame_clause ]
    )

where frame_clause is one of:

  { RANGE | ROWS | GROUPS } frame_start
  { RANGE | ROWS | GROUPS } BETWEEN frame_start AND frame_end

and frame_start and frame_end can be one of

UNBOUNDED PRECEDING
offset PRECEDING
CURRENT ROW
offset FOLLOWING
UNBOUNDED FOLLOWING

where offset is an non-negative integer.

RANGE and GROUPS modes require an ORDER BY clause (with RANGE the ORDER BY must specify exactly one column).

Aggregate functions

All aggregate functions can be used as window functions.

Ranking Functions

• cume_dist
• dense_rank
• ntile
• percent_rank
• rank
• row_number

cume_dist

Relative rank of the current row: (number of rows preceding or peer with current row) / (total rows).

cume_dist()

dense_rank

Returns the rank of the current row without gaps. This function ranks rows in a dense manner, meaning consecutive ranks are assigned even for identical values.

dense_rank()

ntile

Integer ranging from 1 to the argument value, dividing the partition as equally as possible

ntile(expression)

Arguments

• expression: An integer describing the number groups the partition should be split into

percent_rank

Returns the percentage rank of the current row within its partition. The value ranges from 0 to 1 and is computed as (rank - 1) / (total_rows - 1).

percent_rank()

rank

Returns the rank of the current row within its partition, allowing gaps between ranks. This function provides a ranking similar to row_number, but skips ranks for identical values.

rank()

row_number

Number of the current row within its partition, counting from 1.

row_number()

Analytical Functions

• first_value
• lag
• last_value
• lead
• nth_value

first_value

Returns value evaluated at the row that is the first row of the window frame.

first_value(expression)

Arguments

• expression: Expression to operate on

lag

Returns value evaluated at the row that is offset rows before the current row within the partition; if there is no such row, instead return default (which must be of the same type as value).

lag(expression, offset, default)

Arguments

• expression: Expression to operate on
• offset: Integer. Specifies how many rows back the value of expression should be retrieved. Defaults to 1.
• default: The default value if the offset is not within the partition. Must be of the same type as expression.

last_value

Returns value evaluated at the row that is the last row of the window frame.

last_value(expression)

Arguments

• expression: Expression to operate on

lead

Returns value evaluated at the row that is offset rows after the current row within the partition; if there is no such row, instead return default (which must be of the same type as value).

lead(expression, offset, default)

Arguments

• expression: Expression to operate on
• offset: Integer. Specifies how many rows forward the value of expression should be retrieved. Defaults to 1.
• default: The default value if the offset is not within the partition. Must be of the same type as expression.

nth_value

Returns value evaluated at the row that is the nth row of the window frame (counting from 1); null if no such row.

nth_value(expression, n)

Arguments

• expression: The name the column of which nth value to retrieve
• n: Integer. Specifies the n in nth