String functions
Cloudflare Pipelines scalar function implementations are based on Apache DataFusion ↗ (via Arroyo ↗) and these docs are derived from the DataFusion function reference.
Returns the ASCII value 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 string operators.
Related functions: chr
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 string operators.
Related functions: length, octet_length
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 string operators.
- trim_str: String expression to trim from the beginning and end of the input string. Can be a constant, column, or function, and any combination of arithmetic operators. Default is whitespace characters.
Related functions: ltrim, rtrim
Aliases
- trim
Alias of length.
Alias of length.
Concatenates multiple strings together.
concat(str[, ..., str_n])
Arguments
- str: String expression to concatenate. Can be a constant, column, or function, and any combination of string operators.
- str_n: Subsequent string column or literal string to concatenate.
Related functions: concat_ws
Concatenates multiple strings together with a specified separator.
concat(separator, str[, ..., str_n])
Arguments
- separator: Separator to insert between concatenated strings.
- str: String expression to concatenate. Can be a constant, column, or function, and any combination of string operators.
- str_n: Subsequent string column or literal string to concatenate.
Related functions: concat
Returns the character with the specified ASCII or Unicode code value.
chr(expression)
Arguments
- expression: Expression containing the ASCII or Unicode code value to operate on. Can be a constant, column, or function, and any combination of arithmetic or string operators.
Related functions: ascii
Tests if a string ends with a substring.
ends_with(str, substr)
Arguments
- str: String expression to test. Can be a constant, column, or function, and any combination of string operators.
- substr: Substring to test for.
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 string operators.
Related functions: lower, upper
Alias of strpos.
Arguments
- str: String expression to operate on. Can be a constant, column, or function, and any combination of string operators.
- substr: Substring expression to search for. Can be a constant, column, or function, and any combination of string operators.
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 string operators.
- n: Number of characters to return.
Related functions: right
Returns the number of characters in a string.
length(str)
Arguments
- str: String expression to operate on. Can be a constant, column, or function, and any combination of string operators.
Aliases
- char_length
- character_length
Related functions: bit_length, octet_length
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 string operators.
Related functions: initcap, upper
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 string 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.
Related functions: rpad
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 string 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.
Related functions: btrim, rtrim
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 string operators.
Related functions: bit_length, length
Returns a string with an input string repeated a specified number.
repeat(str, n)
Arguments
- str: String expression to repeat. Can be a constant, column, or function, and any combination of string operators.
- n: Number of times to repeat the input string.
Replaces all occurrences of a specified substring in a string with a new substring.
replace(str, substr, replacement)
Arguments
- str: String expression to repeat. Can be a constant, column, or function, and any combination of string operators.
- substr: Substring expression to replace in the input string. Can be a constant, column, or function, and any combination of string operators.
- replacement: Replacement substring expression. Can be a constant, column, or function, and any combination of string operators.
Reverses the character order of a string.
reverse(str)
Arguments
- str: String expression to repeat. Can be a constant, column, or function, and any combination of string operators.
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 string operators.
- n: Number of characters to return.
Related functions: left
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 string 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.
Related functions: lpad
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 string 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.
Related functions: btrim, ltrim
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 spit. Can be a constant, column, or function, and any combination of string operators.
- delimiter: String or character to split on.
- pos: Position of the part to return.
Tests if a string starts with a substring.
starts_with(str, substr)
Arguments
- str: String expression to test. Can be a constant, column, or function, and any combination of string operators.
- substr: Substring to test for.
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 string operators.
- substr: Substring expression to search for. Can be a constant, column, or function, and any combination of string operators.
Aliases
- instr
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 string 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.
Translates characters in a string to specified translation characters.
translate(str, chars, translation)
- str: String expression to operate on. Can be a constant, column, or function, and any combination of string operators.
- chars: Characters to translate.
- translation: Translation characters. Translation characters replace only characters at the same position in the chars string.
Converts an integer to a hexadecimal string.
to_hex(int)
Arguments
- int: Integer expression to convert. Can be a constant, column, or function, and any combination of arithmetic operators.
Alias of btrim.
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 string operators.
Related functions: initcap, lower
Returns UUID v4 string value which is unique per row.
uuid()
Returns the string which is replaced by another string from the specified position and specified count length.
For example, overlay('Txxxxas' placing 'hom' from 2 for 4) → Thomas
overlay(str PLACING substr FROM pos [FOR count])
Arguments
- str: String expression to operate on.
- substr: the string to replace part of str.
- pos: the start position to replace of str.
- count: the count of characters to be replaced from start position of str. If not specified, will use substr length instead.
Returns the Levenshtein distance between the two given strings.
For example, levenshtein('kitten', 'sitting') = 3
levenshtein(str1, str2)
Arguments
- str1: String expression to compute Levenshtein distance with str2.
- str2: String expression to compute Levenshtein distance with str1.
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.
For example, substr_index('www.apache.org', '.', 1) = www
, substr_index('www.apache.org', '.', -1) = org
substr_index(str, delim, count)
Arguments
- str: String expression to operate on.
- delim: the string to find in str to split str.
- count: The number of times to search for the delimiter. Can be both a positive or negative number.
Returns a value in the range of 1 to N if the string str is in the string list strlist consisting of N substrings.
For example, find_in_set('b', 'a,b,c,d') = 2
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.
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