Module datafusion_expr::expr_fn

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Functions for creating logical expressions

Functions

abs

absolute value

acos

inverse cosine

and

Return a new expression with a logical AND

approx_distinct

Returns the approximate number of distinct input values. This function provides an approximation of count(DISTINCT x). Zero is returned if all input values are null. This function should produce a standard error of 0.81%, which is the standard deviation of the (approximately normal) error distribution over all possible sets. It does not guarantee an upper bound on the error for any specific input set.

approx_median

Calculate an approximation of the median for expr.

approx_percentile_cont

Calculate an approximation of the specified percentile for expr.

approx_percentile_cont_with_weight

Calculate an approximation of the specified percentile for expr and weight_expr.

array

Returns an array of fixed size with each argument on it.

arrow_typeof

data type

ascii

Scalar function definition for ascii

asin

inverse sine

atan

inverse tangent

atan2

Scalar function definition for atan2

avg

Create an expression to represent the avg() aggregate function

binary_expr

Return a new expression l r

bit_length

Scalar function definition for bit_length

btrim

Scalar function definition for btrim

call_fn

Calls a named built in function

case

Create a CASE WHEN statement with literal WHEN expressions for comparison to the base expression.

cast

Create a cast expression

ceil

nearest integer greater than or equal to argument

character_length

Scalar function definition for character_length

chr

Scalar function definition for chr

coalesce

Returns coalesce(args...), which evaluates to the value of the first Expr which is not NULL

col

Create a column expression based on a qualified or unqualified column name

combine_filters

Combines an array of filter expressions into a single filter expression consisting of the input filter expressions joined with logical AND. Returns None if the filters array is empty.

concat

Concatenates the text representations of all the arguments. NULL arguments are ignored.

concat_expr

Scalar function definition for concat_expr

concat_ws

Concatenates all but the first argument, with separators. The first argument is used as the separator string, and should not be NULL. Other NULL arguments are ignored.

concat_ws_expr

Scalar function definition for concat_ws_expr

cos

cosine

count

Create an expression to represent the count() aggregate function

count_distinct

Create an expression to represent the count(distinct) aggregate function

create_udaf

Creates a new UDAF with a specific signature, state type and return type. The signature and state type must match the Accumulator's implementation.

create_udf

Creates a new UDF with a specific signature and specific return type. This is a helper function to create a new UDF. The function create_udf returns a subset of all possible ScalarFunction:

cube

Create a grouping set for all combination of exprs

date_bin

Scalar function definition for date_bin

date_part

Scalar function definition for date_part

date_trunc

Scalar function definition for date_trunc

digest

Scalar function definition for digest

exists

Create an EXISTS subquery expression

exp

base 2 logarithm

floor

nearest integer less than or equal to argument

from_unixtime

Scalar function definition for from_unixtime

grouping_set

Create a grouping set

in_list

Create an in_list expression

in_subquery

Create an IN subquery expression

initcap

Scalar function definition for initcap

left

Scalar function definition for left

length

Scalar function definition for length

natural logarithm

base 10 logarithm

base 10 logarithm

Scalar function definition for lower

lpad

Scalar function definition for lpad

ltrim

Scalar function definition for ltrim

max

Create an expression to represent the max() aggregate function

md5

Scalar function definition for md5

min

Create an expression to represent the min() aggregate function

not_exists

Create a NOT EXISTS subquery expression

not_in_subquery

Create a NOT IN subquery expression

now

current time

now_expr

Scalar function definition for now_expr

nullif

The NULLIF function returns a null value if value1 equals value2; otherwise it returns value1. This can be used to perform the inverse operation of the COALESCE expression.

octet_length

Scalar function definition for octet_length

or

Return a new expression with a logical OR

power

Scalar function definition for power

random

Returns a random value in the range 0.0 <= x < 1.0

regexp_match

Scalar function definition for regexp_match

regexp_replace

Scalar function definition for regexp_replace