Module datafusion_expr::expr_fn

Functions for creating logical expressions

Functions

• abs
  absolute value
• acos
  inverse cosine
• acosh
  inverse hyperbolic 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
  ASCII code value of the character
• asin
  inverse sine
• asinh
  inverse hyperbolic sine
• atan
  inverse tangent
• atan2
  inverse tangent of a division given in the argument
• atanh
  inverse hyperbolic tangent
• avg
  Create an expression to represent the avg() aggregate function
• binary_expr
  Return a new expression left <op> right
• bit_length
  the number of bits in the string
• bitwise_and
  Return a new expression with bitwise AND
• bitwise_or
  Return a new expression with bitwise OR
• bitwise_shift_left
  Return a new expression with bitwise SHIFT LEFT
• bitwise_shift_right
  Return a new expression with bitwise SHIFT RIGHT
• bitwise_xor
  Return a new expression with bitwise XOR
• btrim
  removes all characters, spaces by default, from both sides of a string
• 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
• cbrt
  cube root of a number
• ceil
  nearest integer greater than or equal to argument
• character_length
  the number of characters in the string
• chr
  converts the Unicode code point to a UTF8 character
• 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. Will normalize unquoted identifiers according to SQL rules (identifiers will become lowercase).
• concat
  Concatenates the text representations of all the arguments. NULL arguments are ignored.
• concat_expr
  concatenates several strings
• concat_ws
  Concatenates all but the first argument, with separators. The first argument is used as the separator. NULL arguments in values are ignored.
• concat_ws_expr
  concatenates several strings, placing a seperator between each one
• cos
  cosine
• cosh
  hyperbolic 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
• current_date
  returns current UTC date as a [DataType::Date32] value
• current_time
  returns current UTC time as a [DataType::Time64] value
• date_bin
  coerces an arbitrary timestamp to the start of the nearest specified interval
• date_part
  extracts a subfield from the date
• date_trunc
  truncates the date to a specified level of precision
• degrees
  converts radians to degrees
• digest
  compute the binary hash of input, using the algorithm
• exists
  Create an EXISTS subquery expression
• exp
  exponential
• factorial
  factorial
• floor
  nearest integer less than or equal to argument
• from_unixtime
  returns the unix time in format
• gcd
  greatest common divisor
• grouping_set
  Create a grouping set
• ident
  Create an unqualified column expression from the provided name, without normalizing the column.
• in_list
  Create an in_list expression
• in_subquery
  Create an IN subquery expression
• initcap
  converts the first letter of each word in string in uppercase and the remaining characters in lowercase
• is_false
  Create is false expression
• is_not_false
  Create is not false expression
• is_not_true
  Create is not true expression
• is_not_unknown
  Create is not unknown expression
• is_null
  Create is null expression
• is_true
  Create is true expression
• is_unknown
  Create is unknown expression
• lcm
  least common multiple
• left
  returns the first n characters in the string
• ln
  natural logarithm
• log
  logarithm of a x for a particular base
• log2
  base 2 logarithm
• log10
  base 10 logarithm
• lower
  convert the string to lower case
• lpad
  fill up a string to the length by prepending the characters
• ltrim
  removes all characters, spaces by default, from the beginning of a string
• max
  Create an expression to represent the max() aggregate function
• md5
  returns the MD5 hash of a string
• median
  Calculate the median for expr.
• 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
  returns current timestamp in nanoseconds, using the same value for all instances of now() in same statement
• nullif
  returns NULL if value1 equals value2; otherwise it returns value1. This can be used to perform the inverse operation of the COALESCE expression.
• octet_length
  returns the number of bytes of a string
• or
  Return a new expression with a logical OR
• out_ref_col
  Create an out reference column which hold a reference that has been resolved to a field outside of the current plan.
• pi
  Returns an approximate value of π
• power
  base raised to the power of exponent
• radians
  converts degrees to radians
• random
  Returns a random value in the range 0.0 <= x < 1.0
• regexp_match
  matches a regular expression against a string and returns matched substrings.
• regexp_replace
  replace strings that match a regular expression
• repeat
  repeats the string to n times
• replace
  replaces all occurrences of from with to in the string
• reverse
  reverses the string
• right
  returns the last n characters in the string
• rollup
  Create a grouping set for rollup
• round
  round to nearest integer
• rpad
  fill up a string to the length by appending the characters
• rtrim
  removes all characters, spaces by default, from the end of a string
• scalar_subquery
  Create a scalar subquery expression
• sha224
  SHA-224 hash
• sha256
  SHA-256 hash
• sha384
  SHA-384 hash
• sha512
  SHA-512 hash
• signum
  sign of the argument (-1, 0, +1)
• sin
  sine
• sinh
  hyperbolic sine
• split_part
  splits a string based on a delimiter and picks out the desired field based on the index.
• sqrt
  square root of a number
• starts_with
  whether the string starts with the prefix
• stddev
  Create an expression to represent the stddev() aggregate function
• strpos
  finds the position from where the substring matches the string
• substr
  substring from the position to the end
• substring
  substring from the position with length characters
• sum
  Create an expression to represent the sum() aggregate function
• tan
  tangent
• tanh
  hyperbolic tangent
• to_hex
  returns the hexdecimal representation of an integer
• to_timestamp_micros
  converts a string to a Timestamp(Microseconds, None)
• to_timestamp_millis
  converts a string to a Timestamp(Milliseconds, None)
• to_timestamp_seconds
  converts a string to a Timestamp(Seconds, None)
• translate
  replaces the characters in from with the counterpart in to
• trim
  removes all characters, space by default from the string
• trunc
  truncate toward zero
• try_cast
  Create a try cast expression
• upper
  converts the string to upper case
• uuid
  Returns uuid v4 as a string value
• when
  Create a CASE WHEN statement with boolean WHEN expressions and no base expression.