String functions

GoogleSQL for Bigtable supports string functions. These string functions work on two different values: STRING and BYTES data types. STRING values must be well-formed UTF-8.

Functions that return position values, such as STRPOS, encode those positions as INT64. The value 1 refers to the first character (or byte), 2 refers to the second, and so on. The value 0 indicates an invalid position. When working on STRING types, the returned positions refer to character positions.

All string comparisons are done byte-by-byte, without regard to Unicode canonical equivalence.

Function list

Name	Summary
`ARRAY_TO_STRING`	Produces a concatenation of the elements in an array as a `STRING` value. For more information, see Array functions.
`ASCII`	Gets the ASCII code for the first character or byte in a `STRING` or `BYTES` value.
`BYTE_LENGTH`	Gets the number of `BYTES` in a `STRING` or `BYTES` value.
`CHAR_LENGTH`	Gets the number of characters in a `STRING` value.
`CHR`	Converts a Unicode code point to a character.
`CODE_POINTS_TO_BYTES`	Converts an array of extended ASCII code points to a `BYTES` value.
`CODE_POINTS_TO_STRING`	Converts an array of extended ASCII code points to a `STRING` value.
`CONCAT`	Concatenates one or more `STRING` or `BYTES` values into a single result.
`ENDS_WITH`	Checks if a `STRING` or `BYTES` value is the suffix of another value.
`FORMAT`	Formats data and produces the results as a `STRING` value.
`FROM_BASE32`	Converts a base32-encoded `STRING` value into a `BYTES` value.
`FROM_BASE64`	Converts a base64-encoded `STRING` value into a `BYTES` value.
`FROM_HEX`	Converts a hexadecimal-encoded `STRING` value into a `BYTES` value.
`INITCAP`	Formats a `STRING` as proper case, which means that the first character in each word is uppercase and all other characters are lowercase.
`INSTR`	Finds the position of a subvalue inside another value, optionally starting the search at a given offset or occurrence.
`LEFT`	Gets the specified leftmost portion from a `STRING` or `BYTES` value.
`LENGTH`	Gets the length of a `STRING` or `BYTES` value.
`LOWER`	Formats alphabetic characters in a `STRING` value as lowercase. Formats ASCII characters in a `BYTES` value as lowercase.
`LPAD`	Prepends a `STRING` or `BYTES` value with a pattern.
`LTRIM`	Identical to the `TRIM` function, but only removes leading characters.
`NORMALIZE`	Case-sensitively normalizes the characters in a `STRING` value.
`NORMALIZE_AND_CASEFOLD`	Case-insensitively normalizes the characters in a `STRING` value.
`OCTET_LENGTH`	Alias for `BYTE_LENGTH`.
`REGEXP_CONTAINS`	Checks if a value is a partial match for a regular expression.
`REGEXP_EXTRACT`	Produces a substring that matches a regular expression.
`REGEXP_EXTRACT_ALL`	Produces an array of all substrings that match a regular expression.
`REGEXP_INSTR`	Finds the position of a regular expression match in a value, optionally starting the search at a given offset or occurrence.
`REGEXP_REPLACE`	Produces a `STRING` value where all substrings that match a regular expression are replaced with a specified value.
`REPEAT`	Produces a `STRING` or `BYTES` value that consists of an original value, repeated.
`REPLACE`	Replaces all occurrences of a pattern with another pattern in a `STRING` or `BYTES` value.
`REVERSE`	Reverses a `STRING` or `BYTES` value.
`RIGHT`	Gets the specified rightmost portion from a `STRING` or `BYTES` value.
`RPAD`	Appends a `STRING` or `BYTES` value with a pattern.
`RTRIM`	Identical to the `TRIM` function, but only removes trailing characters.
`SAFE_CONVERT_BYTES_TO_STRING`	Converts a `BYTES` value to a `STRING` value and replace any invalid UTF-8 characters with the Unicode replacement character, `U+FFFD`.
`SOUNDEX`	Gets the Soundex codes for words in a `STRING` value.
`SPLIT`	Splits a `STRING` or `BYTES` value, using a delimiter.
`STARTS_WITH`	Checks if a `STRING` or `BYTES` value is a prefix of another value.
`STRING` (Timestamp)	Converts a `TIMESTAMP` value to a `STRING` value. For more information, see Timestamp functions.
`STRPOS`	Finds the position of the first occurrence of a subvalue inside another value.
`SUBSTR`	Gets a portion of a `STRING` or `BYTES` value.
`SUBSTRING`	Alias for `SUBSTR`
`TO_BASE32`	Converts a `BYTES` value to a base32-encoded `STRING` value.
`TO_BASE64`	Converts a `BYTES` value to a base64-encoded `STRING` value.
`TO_CODE_POINTS`	Converts a `STRING` or `BYTES` value into an array of extended ASCII code points.
`TO_HEX`	Converts a `BYTES` value to a hexadecimal `STRING` value.
`TO_INT64`	Converts the big-endian bytes of a 64-bit signed integer into an `INT64` value.
`TO_VECTOR32`	Converts the big-endian bytes of one or more 32-bit IEEE 754 floating point numbers into an `ARRAY<FLOAT32>` value.
`TO_VECTOR64`	Converts the big-endian bytes of one or more 64-bit IEEE 754 floating point numbers into an `ARRAY<FLOAT64>` value.
`TRANSLATE`	Within a value, replaces each source character with the corresponding target character.
`TRIM`	Removes the specified leading and trailing Unicode code points or bytes from a `STRING` or `BYTES` value.
`UNICODE`	Gets the Unicode code point for the first character in a value.
`UPPER`	Formats alphabetic characters in a `STRING` value as uppercase. Formats ASCII characters in a `BYTES` value as uppercase.

`ASCII`

ASCII(value)

Description

Returns the ASCII code for the first character or byte in value. Returns 0 if value is empty or the ASCII code is 0 for the first character or byte.

Return type

INT64

Examples

SELECT ASCII('abcd') as A, ASCII('a') as B, ASCII('') as C, ASCII(NULL) as D;

/*-------+-------+-------+-------*
 | A     | B     | C     | D     |
 +-------+-------+-------+-------+
 | 97    | 97    | 0     | NULL  |
 *-------+-------+-------+-------*/

`BYTE_LENGTH`

BYTE_LENGTH(value)

Description

Gets the number of BYTES in a STRING or BYTES value, regardless of whether the value is a STRING or BYTES type.

Return type

INT64

Examples

SELECT BYTE_LENGTH('абвгд') AS string_example;

/*----------------*
 | string_example |
 +----------------+
 | 10             |
 *----------------*/

SELECT BYTE_LENGTH(b'абвгд') AS bytes_example;

/*----------------*
 | bytes_example  |
 +----------------+
 | 10             |
 *----------------*/

`CHAR_LENGTH`

CHAR_LENGTH(value)

Description

Gets the number of characters in a STRING value.

Return type

INT64

Examples

SELECT CHAR_LENGTH('абвгд') AS char_length;

/*-------------*
 | char_length |
 +-------------+
 | 5           |
 *------------ */

`CHR`

CHR(value)

Description

Takes a Unicode code point and returns the character that matches the code point. Each valid code point should fall within the range of [0, 0xD7FF] and [0xE000, 0x10FFFF]. Returns an empty string if the code point is 0. If an invalid Unicode code point is specified, an error is returned.

To work with an array of Unicode code points, see CODE_POINTS_TO_STRING

Return type

STRING

Examples

SELECT CHR(65) AS A, CHR(255) AS B, CHR(513) AS C, CHR(1024)  AS D;

/*-------+-------+-------+-------*
 | A     | B     | C     | D     |
 +-------+-------+-------+-------+
 | A     | ÿ     | ȁ     | Ѐ     |
 *-------+-------+-------+-------*/

SELECT CHR(97) AS A, CHR(0xF9B5) AS B, CHR(0) AS C, CHR(NULL) AS D;

/*-------+-------+-------+-------*
 | A     | B     | C     | D     |
 +-------+-------+-------+-------+
 | a     | 例    |       | NULL  |
 *-------+-------+-------+-------*/

`CODE_POINTS_TO_BYTES`

CODE_POINTS_TO_BYTES(ascii_code_points)

Description

Takes an array of extended ASCII code points as ARRAY<INT64> and returns BYTES.

To convert from BYTES to an array of code points, see TO_CODE_POINTS.

Return type

BYTES

Examples

The following is a basic example using CODE_POINTS_TO_BYTES.

SELECT CODE_POINTS_TO_BYTES([65, 98, 67, 100]) AS bytes;

-- Note that the result of CODE_POINTS_TO_BYTES is of type BYTES, displayed as a base64-encoded string.
-- In BYTES format, b'AbCd' is the result.
/*----------*
 | bytes    |
 +----------+
 | QWJDZA== |
 *----------*/

The following example uses a rotate-by-13 places (ROT13) algorithm to encode a string.

`CODE_POINTS_TO_STRING`

CODE_POINTS_TO_STRING(unicode_code_points)

Description

Takes an array of Unicode code points as ARRAY<INT64> and returns a STRING.

To convert from a string to an array of code points, see TO_CODE_POINTS.

Return type

STRING

Examples

The following are basic examples using CODE_POINTS_TO_STRING.

SELECT CODE_POINTS_TO_STRING([65, 255, 513, 1024]) AS string;

/*--------*
 | string |
 +--------+
 | AÿȁЀ   |
 *--------*/

SELECT CODE_POINTS_TO_STRING([97, 0, 0xF9B5]) AS string;

/*--------*
 | string |
 +--------+
 | a例    |
 *--------*/

SELECT CODE_POINTS_TO_STRING([65, 255, NULL, 1024]) AS string;

/*--------*
 | string |
 +--------+
 | NULL   |
 *--------*/

The following example computes the frequency of letters in a set of words.

`CONCAT`

CONCAT(value1[, ...])

Description

Concatenates one or more values into a single result. All values must be BYTES or data types that can be cast to STRING.

The function returns NULL if any input argument is NULL.

Return type

STRING or BYTES

Examples

SELECT CONCAT('T.P.', ' ', 'Bar') as author;

/*---------------------*
 | author              |
 +---------------------+
 | T.P. Bar            |
 *---------------------*/

SELECT CONCAT('Summer', ' ', 1923) as release_date;

/*---------------------*
 | release_date        |
 +---------------------+
 | Summer 1923         |
 *---------------------*/


With Employees AS
  (SELECT
    'John' AS first_name,
    'Doe' AS last_name
  UNION ALL
  SELECT
    'Jane' AS first_name,
    'Smith' AS last_name
  UNION ALL
  SELECT
    'Joe' AS first_name,
    'Jackson' AS last_name)

SELECT
  CONCAT(first_name, ' ', last_name)
  AS full_name
FROM Employees;

/*---------------------*
 | full_name           |
 +---------------------+
 | John Doe            |
 | Jane Smith          |
 | Joe Jackson         |
 *---------------------*/

`ENDS_WITH`

ENDS_WITH(value, suffix)

Description

Takes two STRING or BYTES values. Returns TRUE if suffix is a suffix of value.

This function supports specifying collation.

Return type

BOOL

Examples

SELECT ENDS_WITH('apple', 'e') as example

/*---------*
 | example |
 +---------+
 |    True |
 *---------*/

`FORMAT`

FORMAT(format_string_expression, data_type_expression[, ...])

Description

FORMAT formats a data type expression as a string.

format_string_expression: Can contain zero or more format specifiers. Each format specifier is introduced by the % symbol, and must map to one or more of the remaining arguments. In general, this is a one-to-one mapping, except when the * specifier is present. For example, %.*i maps to two arguments—a length argument and a signed integer argument. If the number of arguments related to the format specifiers is not the same as the number of arguments, an error occurs.
data_type_expression: The value to format as a string. This can be any GoogleSQL data type.

Return type

STRING

Examples

Description	Statement	Result
Simple integer	FORMAT('%d', 10)	10
Integer with left blank padding	FORMAT('\|%10d\|', 11)	\| 11\|
Integer with left zero padding	FORMAT('+%010d+', 12)	+0000000012+
Integer with commas	FORMAT("%'d", 123456789)	123,456,789
STRING	FORMAT('-%s-', 'abcd efg')	-abcd efg-
FLOAT64	FORMAT('%f %E', 1.1, 2.2)	1.100000 2.200000E+00
DATE	FORMAT('%t', date '2015-09-01')	2015-09-01
TIMESTAMP	FORMAT('%t', timestamp '2015-09-01 12:34:56 America/Los_Angeles')	2015‑09‑01 19:34:56+00

The FORMAT() function does not provide fully customizable formatting for all types and values, nor formatting that is sensitive to locale.

If custom formatting is necessary for a type, you must first format it using type-specific format functions, such as FORMAT_DATE() or FORMAT_TIMESTAMP(). For example:

SELECT FORMAT('date: %s!', FORMAT_DATE('%B %d, %Y', date '2015-01-02'));

Returns

date: January 02, 2015!

Supported format specifiers

%[flags][width][.precision]specifier

A format specifier adds formatting when casting a value to a string. It can optionally contain these sub-specifiers:

Additional information about format specifiers:

Format specifiers

Specifier	Description	Examples	Types
`d` or `i`	Decimal integer	392	`INT64`
`o`	Octal Note: If an `INT64` value is negative, an error is produced.	610	`INT64`
`x`	Hexadecimal integer Note: If an `INT64` value is negative, an error is produced.	7fa	`INT64`
`X`	Hexadecimal integer (uppercase) Note: If an `INT64` value is negative, an error is produced.	7FA	`INT64`
`f`	Decimal notation, in [-](integer part).(fractional part) for finite values, and in lowercase for non-finite values	392.650000 inf nan	`FLOAT32` `FLOAT64`
`F`	Decimal notation, in [-](integer part).(fractional part) for finite values, and in uppercase for non-finite values	392.650000 INF NAN	`FLOAT32` `FLOAT64`
`e`	Scientific notation (mantissa/exponent), lowercase	3.926500e+02 inf nan	`FLOAT32` `FLOAT64`
`E`	Scientific notation (mantissa/exponent), uppercase	3.926500E+02 INF NAN	`FLOAT32` `FLOAT64`
`g`	Either decimal notation or scientific notation, depending on the input value's exponent and the specified precision. Lowercase. See %g and %G behavior for details.	392.65 3.9265e+07 inf nan	`FLOAT32` `FLOAT64`
`G`	Either decimal notation or scientific notation, depending on the input value's exponent and the specified precision. Uppercase. See %g and %G behavior for details.	392.65 3.9265E+07 INF NAN	`FLOAT32` `FLOAT64`
`s`	String of characters	sample	`STRING`
`t`	Returns a printable string representing the value. Often looks similar to casting the argument to `STRING`. See %t and %T behavior.	sample 2014‑01‑01	Any type
`T`	Produces a string that is a valid GoogleSQL constant with a similar type to the value's type (maybe wider, or maybe string). See %t and %T behavior.	'sample' b'bytes sample' 1234 2.3 date '2014‑01‑01'	Any type
`%`	'%%' produces a single '%'	%	n/a

The format specifier can optionally contain the sub-specifiers identified above in the specifier prototype.

These sub-specifiers must comply with the following specifications.

Flags

Flags	Description
`-`	Left-justify within the given field width; Right justification is the default (see width sub-specifier)
`+`	Forces to precede the result with a plus or minus sign (`+` or `-`) even for positive numbers. By default, only negative numbers are preceded with a `-` sign
<space>	If no sign is going to be written, a blank space is inserted before the value
`#`	For `%o`, `%x`, and `%X`, this flag means to precede the value with 0, 0x or 0X respectively for values different than zero. For `%f`, `%F`, `%e`, and `%E`, this flag means to add the decimal point even when there is no fractional part, unless the value is non-finite. For `%g` and `%G`, this flag means to add the decimal point even when there is no fractional part unless the value is non-finite, and never remove the trailing zeros after the decimal point.
`0`	Left-pads the number with zeroes (0) instead of spaces when padding is specified (see width sub-specifier)
`'`	Formats integers using the appropriating grouping character. For example: `FORMAT("%'d", 12345678)` returns `12,345,678` `FORMAT("%'x", 12345678)` returns `bc:614e` `FORMAT("%'o", 55555)` returns `15,4403` This flag is only relevant for decimal, hex, and octal values.

Flags may be specified in any order. Duplicate flags are not an error. When flags are not relevant for some element type, they are ignored.

Width

Width	Description
<number>	Minimum number of characters to be printed. If the value to be printed is shorter than this number, the result is padded with blank spaces. The value is not truncated even if the result is larger
`*`	The width is not specified in the format string, but as an additional integer value argument preceding the argument that has to be formatted

Precision

Precision	Description
`.`<number>	For integer specifiers `%d`, `%i`, `%o`, `%u`, `%x`, and `%X`: precision specifies the minimum number of digits to be written. If the value to be written is shorter than this number, the result is padded with trailing zeros. The value is not truncated even if the result is longer. A precision of 0 means that no character is written for the value 0. For specifiers `%a`, `%A`, `%e`, `%E`, `%f`, and `%F`: this is the number of digits to be printed after the decimal point. The default value is 6. For specifiers `%g` and `%G`: this is the number of significant digits to be printed, before the removal of the trailing zeros after the decimal point. The default value is 6.
`.*`	The precision is not specified in the format string, but as an additional integer value argument preceding the argument that has to be formatted

%g and %G behavior

The %g and %G format specifiers choose either the decimal notation (like the %f and %F specifiers) or the scientific notation (like the %e and %E specifiers), depending on the input value's exponent and the specified precision.

Let p stand for the specified precision (defaults to 6; 1 if the specified precision is less than 1). The input value is first converted to scientific notation with precision = (p - 1). If the resulting exponent part x is less than -4 or no less than p, the scientific notation with precision = (p - 1) is used; otherwise the decimal notation with precision = (p - 1 - x) is used.

Unless # flag is present, the trailing zeros after the decimal point are removed, and the decimal point is also removed if there is no digit after it.

%t and %T behavior

The %t and %T format specifiers are defined for all types. The width, precision, and flags act as they do for %s: the width is the minimum width and the STRING will be padded to that size, and precision is the maximum width of content to show and the STRING will be truncated to that size, prior to padding to width.

The %t specifier is always meant to be a readable form of the value.

The %T specifier is always a valid SQL literal of a similar type, such as a wider numeric type. The literal will not include casts or a type name, except for the special case of non-finite floating point values.

The STRING is formatted as follows:

Type	%t	%T
`NULL` of any type	NULL	NULL
`INT64`	123	123
FLOAT32, FLOAT64	123.0 (always with .0) 123e+10 `inf` `-inf` `NaN`	123.0 (always with .0) 123e+10 CAST("inf" AS <type>) CAST("-inf" AS <type>) CAST("nan" AS <type>)
STRING	unquoted string value	quoted string literal
BYTES	unquoted escaped bytes e.g., abc\x01\x02	quoted bytes literal e.g., b"abc\x01\x02"
BOOL	boolean value	boolean value
ENUM	EnumName	"EnumName"
DATE	2011-02-03	DATE "2011-02-03"
TIMESTAMP	2011-02-03 04:05:06+00	TIMESTAMP "2011-02-03 04:05:06+00"
ARRAY	[value, value, ...] where values are formatted with %t	[value, value, ...] where values are formatted with %T
STRUCT	(value, value, ...) where fields are formatted with %t	(value, value, ...) where fields are formatted with %T Special cases: Zero fields: STRUCT() One field: STRUCT(value)

Error conditions

If a format specifier is invalid, or is not compatible with the related argument type, or the wrong number or arguments are provided, then an error is produced. For example, the following <format_string> expressions are invalid:

FORMAT('%s', 1)

FORMAT('%')

NULL argument handling

A NULL format string results in a NULL output STRING. Any other arguments are ignored in this case.

The function generally produces a NULL value if a NULL argument is present. For example, FORMAT('%i', NULL_expression) produces a NULL STRING as output.

However, there are some exceptions: if the format specifier is %t or %T (both of which produce STRINGs that effectively match CAST and literal value semantics), a NULL value produces 'NULL' (without the quotes) in the result STRING. For example, the function:

FORMAT('00-%t-00', NULL_expression);

Returns

00-NULL-00

Additional semantic rules

FLOAT64 and FLOAT32 values can be +/-inf or NaN. When an argument has one of those values, the result of the format specifiers %f, %F, %e, %E, %g, %G, and %t are inf, -inf, or nan (or the same in uppercase) as appropriate. This is consistent with how GoogleSQL casts these values to STRING. For %T, GoogleSQL returns quoted strings for FLOAT64 values that don't have non-string literal representations.

`FROM_BASE32`

FROM_BASE32(string_expr)

Description

Converts the base32-encoded input string_expr into BYTES format. To convert BYTES to a base32-encoded STRING, use TO_BASE32.

Return type

BYTES

Example

SELECT FROM_BASE32('MFRGGZDF74======') AS byte_data;

-- Note that the result of FROM_BASE32 is of type BYTES, displayed as a base64-encoded string.
/*-----------*
 | byte_data |
 +-----------+
 | YWJjZGX/  |
 *-----------*/

`FROM_BASE64`

FROM_BASE64(string_expr)

Description

Converts the base64-encoded input string_expr into BYTES format. To convert BYTES to a base64-encoded STRING, use [TO_BASE64][string-link-to-base64].

There are several base64 encodings in common use that vary in exactly which alphabet of 65 ASCII characters are used to encode the 64 digits and padding. See RFC 4648 for details. This function expects the alphabet [A-Za-z0-9+/=].

Return type

BYTES

Example

SELECT FROM_BASE64('/+A=') AS byte_data;

-- Note that the result of FROM_BASE64 is of type BYTES, displayed as a base64-encoded string.
/*-----------*
 | byte_data |
 +-----------+
 | /+A=      |
 *-----------*/

To work with an encoding using a different base64 alphabet, you might need to compose FROM_BASE64 with the REPLACE function. For instance, the base64url url-safe and filename-safe encoding commonly used in web programming uses -_= as the last characters rather than +/=. To decode a base64url-encoded string, replace - and _ with + and / respectively.

SELECT FROM_BASE64(REPLACE(REPLACE('_-A=', '-', '+'), '_', '/')) AS binary;

-- Note that the result of FROM_BASE64 is of type BYTES, displayed as a base64-encoded string.
/*--------*
 | binary |
 +--------+
 | /+A=   |
 *--------*/

`FROM_HEX`

FROM_HEX(string)

Description

Converts a hexadecimal-encoded STRING into BYTES format. Returns an error if the input STRING contains characters outside the range (0..9, A..F, a..f). The lettercase of the characters does not matter. If the input STRING has an odd number of characters, the function acts as if the input has an additional leading 0. To convert BYTES to a hexadecimal-encoded STRING, use TO_HEX.

Return type

BYTES

Example

`INITCAP`

INITCAP(value[, delimiters])

Description

Takes a STRING and returns it with the first character in each word in uppercase and all other characters in lowercase. Non-alphabetic characters remain the same.

delimiters is an optional string argument that is used to override the default set of characters used to separate words. If delimiters is not specified, it defaults to the following characters:
<whitespace> [ ] ( ) { } / | \ < > ! ? @ " ^ # $ & ~ _ , . : ; * % + -

If value or delimiters is NULL, the function returns NULL.

Return type

STRING

Examples

SELECT
  'Hello World-everyone!' AS value,
  INITCAP('Hello World-everyone!') AS initcap_value

/*-------------------------------+-------------------------------*
 | value                         | initcap_value                 |
 +-------------------------------+-------------------------------+
 | Hello World-everyone!         | Hello World-Everyone!         |
 *-------------------------------+-------------------------------*/

SELECT
  'Apples1oranges2pears' as value,
  '12' AS delimiters,
  INITCAP('Apples1oranges2pears' , '12') AS initcap_value

/*----------------------+------------+----------------------*
 | value                | delimiters | initcap_value        |
 +----------------------+------------+----------------------+
 | Apples1oranges2pears | 12         | Apples1Oranges2Pears |
 *----------------------+------------+----------------------*/

`INSTR`

INSTR(value, subvalue[, position[, occurrence]])

Description

Returns the lowest 1-based position of subvalue in value. value and subvalue must be the same type, either STRING or BYTES.

If position is specified, the search starts at this position in value, otherwise it starts at 1, which is the beginning of value. If position is negative, the function searches backwards from the end of value, with -1 indicating the last character. position is of type INT64 and cannot be 0.

If occurrence is specified, the search returns the position of a specific instance of subvalue in value. If not specified, occurrence defaults to 1 and returns the position of the first occurrence. For occurrence > 1, the function includes overlapping occurrences. occurrence is of type INT64 and must be positive.

This function supports specifying collation.

Returns 0 if:

No match is found.
If occurrence is greater than the number of matches found.
If position is greater than the length of value.

Returns NULL if:

Any input argument is NULL.

Returns an error if:

position is 0.
occurrence is 0 or negative.

Return type

INT64

Examples

SELECT
  'banana' AS value, 'an' AS subvalue, 1 AS position, 1 AS occurrence,
  INSTR('banana', 'an', 1, 1) AS instr;

/*--------------+--------------+----------+------------+-------*
 | value        | subvalue     | position | occurrence | instr |
 +--------------+--------------+----------+------------+-------+
 | banana       | an           | 1        | 1          | 2     |
 *--------------+--------------+----------+------------+-------*/

SELECT
  'banana' AS value, 'an' AS subvalue, 1 AS position, 2 AS occurrence,
  INSTR('banana', 'an', 1, 2) AS instr;

/*--------------+--------------+----------+------------+-------*
 | value        | subvalue     | position | occurrence | instr |
 +--------------+--------------+----------+------------+-------+
 | banana       | an           | 1        | 2          | 4     |
 *--------------+--------------+----------+------------+-------*/

SELECT
  'banana' AS value, 'an' AS subvalue, 1 AS position, 3 AS occurrence,
  INSTR('banana', 'an', 1, 3) AS instr;

/*--------------+--------------+----------+------------+-------*
 | value        | subvalue     | position | occurrence | instr |
 +--------------+--------------+----------+------------+-------+
 | banana       | an           | 1        | 3          | 0     |
 *--------------+--------------+----------+------------+-------*/

SELECT
  'banana' AS value, 'an' AS subvalue, 3 AS position, 1 AS occurrence,
  INSTR('banana', 'an', 3, 1) AS instr;

/*--------------+--------------+----------+------------+-------*
 | value        | subvalue     | position | occurrence | instr |
 +--------------+--------------+----------+------------+-------+
 | banana       | an           | 3        | 1          | 4     |
 *--------------+--------------+----------+------------+-------*/

SELECT
  'banana' AS value, 'an' AS subvalue, -1 AS position, 1 AS occurrence,
  INSTR('banana', 'an', -1, 1) AS instr;

/*--------------+--------------+----------+------------+-------*
 | value        | subvalue     | position | occurrence | instr |
 +--------------+--------------+----------+------------+-------+
 | banana       | an           | -1       | 1          | 4     |
 *--------------+--------------+----------+------------+-------*/

SELECT
  'banana' AS value, 'an' AS subvalue, -3 AS position, 1 AS occurrence,
  INSTR('banana', 'an', -3, 1) AS instr;

/*--------------+--------------+----------+------------+-------*
 | value        | subvalue     | position | occurrence | instr |
 +--------------+--------------+----------+------------+-------+
 | banana       | an           | -3       | 1          | 4     |
 *--------------+--------------+----------+------------+-------*/

SELECT
  'banana' AS value, 'ann' AS subvalue, 1 AS position, 1 AS occurrence,
  INSTR('banana', 'ann', 1, 1) AS instr;

/*--------------+--------------+----------+------------+-------*
 | value        | subvalue     | position | occurrence | instr |
 +--------------+--------------+----------+------------+-------+
 | banana       | ann          | 1        | 1          | 0     |
 *--------------+--------------+----------+------------+-------*/

SELECT
  'helloooo' AS value, 'oo' AS subvalue, 1 AS position, 1 AS occurrence,
  INSTR('helloooo', 'oo', 1, 1) AS instr;

/*--------------+--------------+----------+------------+-------*
 | value        | subvalue     | position | occurrence | instr |
 +--------------+--------------+----------+------------+-------+
 | helloooo     | oo           | 1        | 1          | 5     |
 *--------------+--------------+----------+------------+-------*/

SELECT
  'helloooo' AS value, 'oo' AS subvalue, 1 AS position, 2 AS occurrence,
  INSTR('helloooo', 'oo', 1, 2) AS instr;

/*--------------+--------------+----------+------------+-------*
 | value        | subvalue     | position | occurrence | instr |
 +--------------+--------------+----------+------------+-------+
 | helloooo     | oo           | 1        | 2          | 6     |
 *--------------+--------------+----------+------------+-------*/

`LEFT`

LEFT(value, length)

Description

Returns a STRING or BYTES value that consists of the specified number of leftmost characters or bytes from value. The length is an INT64 that specifies the length of the returned value. If value is of type BYTES, length is the number of leftmost bytes to return. If value is STRING, length is the number of leftmost characters to return.

If length is 0, an empty STRING or BYTES value will be returned. If length is negative, an error will be returned. If length exceeds the number of characters or bytes from value, the original value will be returned.

Return type

STRING or BYTES

Examples

SELECT LEFT('banana', 3) AS results

/*---------*
 | results |
  +--------+
 | ban     |
 *---------*/

SELECT LEFT(b'\xab\xcd\xef\xaa\xbb', 3) AS results

-- Note that the result of LEFT is of type BYTES, displayed as a base64-encoded string.
/*---------*
 | results |
 +---------+
 | q83v    |
 *---------*/

`LENGTH`

LENGTH(value)

Description

Returns the length of the STRING or BYTES value. The returned value is in characters for STRING arguments and in bytes for the BYTES argument.

Return type

INT64

Examples

SELECT
  LENGTH('абвгд') AS string_example,
  LENGTH(CAST('абвгд' AS BYTES)) AS bytes_example;

/*----------------+---------------*
 | string_example | bytes_example |
 +----------------+---------------+
 | 5              | 10            |
 *----------------+---------------*/

`LOWER`

LOWER(value)

Description

For STRING arguments, returns the original string with all alphabetic characters in lowercase. Mapping between lowercase and uppercase is done according to the Unicode Character Database without taking into account language-specific mappings.

For BYTES arguments, the argument is treated as ASCII text, with all bytes greater than 127 left intact.

Return type

STRING or BYTES

Examples

SELECT
  LOWER('FOO BAR BAZ') AS example
FROM items;

/*-------------*
 | example     |
 +-------------+
 | foo bar baz |
 *-------------*/

`LPAD`

LPAD(original_value, return_length[, pattern])

Description

Returns a STRING or BYTES value that consists of original_value prepended with pattern. The return_length is an INT64 that specifies the length of the returned value. If original_value is of type BYTES, return_length is the number of bytes. If original_value is of type STRING, return_length is the number of characters.

The default value of pattern is a blank space.

Both original_value and pattern must be the same data type.

If return_length is less than or equal to the original_value length, this function returns the original_value value, truncated to the value of return_length. For example, LPAD('hello world', 7); returns 'hello w'.

If original_value, return_length, or pattern is NULL, this function returns NULL.

This function returns an error if:

return_length is negative
pattern is empty

Return type

STRING or BYTES

Examples

SELECT FORMAT('%T', LPAD('c', 5)) AS results

/*---------*
 | results |
 +---------+
 | "    c" |
 *---------*/

SELECT LPAD('b', 5, 'a') AS results

/*---------*
 | results |
 +---------+
 | aaaab   |
 *---------*/

SELECT LPAD('abc', 10, 'ghd') AS results

/*------------*
 | results    |
 +------------+
 | ghdghdgabc |
 *------------*/

SELECT LPAD('abc', 2, 'd') AS results

/*---------*
 | results |
 +---------+
 | ab      |
 *---------*/

SELECT FORMAT('%T', LPAD(b'abc', 10, b'ghd')) AS results

/*---------------*
 | results       |
 +---------------+
 | b"ghdghdgabc" |
 *---------------*/

`LTRIM`

LTRIM(value1[, value2])

Description

Identical to TRIM, but only removes leading characters.

Return type

STRING or BYTES

Examples

SELECT CONCAT('#', LTRIM('   apple   '), '#') AS example

/*-------------*
 | example     |
 +-------------+
 | #apple #    |
 *-------------*/

SELECT LTRIM('***apple***', '*') AS example

/*-----------*
 | example   |
 +-----------+
 | apple***  |
 *-----------*/

SELECT LTRIM('xxxapplexxx', 'xyz') AS example

/*-----------*
 | example   |
 +-----------+
 | applexxx  |
 *-----------*/

`NORMALIZE`

NORMALIZE(value[, normalization_mode])

Description

Takes a string value and returns it as a normalized string. If you do not provide a normalization mode, NFC is used.

Normalization is used to ensure that two strings are equivalent. Normalization is often used in situations in which two strings render the same on the screen but have different Unicode code points.

NORMALIZE supports four optional normalization modes:

Value	Name	Description
`NFC`	Normalization Form Canonical Composition	Decomposes and recomposes characters by canonical equivalence.
`NFKC`	Normalization Form Compatibility Composition	Decomposes characters by compatibility, then recomposes them by canonical equivalence.
`NFD`	Normalization Form Canonical Decomposition	Decomposes characters by canonical equivalence, and multiple combining characters are arranged in a specific order.
`NFKD`	Normalization Form Compatibility Decomposition	Decomposes characters by compatibility, and multiple combining characters are arranged in a specific order.

Return type

STRING

Examples

The following example normalizes different language characters:

SELECT
  NORMALIZE('\u00ea') as a,
  NORMALIZE('\u0065\u0302') as b,
  NORMALIZE('\u00ea') = NORMALIZE('\u0065\u0302') as normalized;

/*---+---+------------*
 | a | b | normalized |
 +---+---+------------+
 | ê | ê | TRUE       |
 *---+---+------------*/

The following examples normalize different space characters:

SELECT NORMALIZE('Raha\u2004Mahan', NFKC) AS normalized_name

/*-----------------*
 | normalized_name |
 +-----------------+
 | Raha Mahan      |
 *-----------------*/

SELECT NORMALIZE('Raha\u2005Mahan', NFKC) AS normalized_name

/*-----------------*
 | normalized_name |
 +-----------------+
 | Raha Mahan      |
 *-----------------*/

SELECT NORMALIZE('Raha\u2006Mahan', NFKC) AS normalized_name

/*-----------------*
 | normalized_name |
 +-----------------+
 | Raha Mahan      |
 *-----------------*/

SELECT NORMALIZE('Raha Mahan', NFKC) AS normalized_name

/*-----------------*
 | normalized_name |
 +-----------------+
 | Raha Mahan      |
 *-----------------*/

`NORMALIZE_AND_CASEFOLD`

NORMALIZE_AND_CASEFOLD(value[, normalization_mode])

Description

Takes a string value and returns it as a normalized string. If you do not provide a normalization mode, NFC is used.

Normalization is used to ensure that two strings are equivalent. Normalization is often used in situations in which two strings render the same on the screen but have different Unicode code points.

Case folding is used for the caseless comparison of strings. If you need to compare strings and case should not be considered, use NORMALIZE_AND_CASEFOLD, otherwise use NORMALIZE.

NORMALIZE_AND_CASEFOLD supports four optional normalization modes:

Value	Name	Description
`NFC`	Normalization Form Canonical Composition	Decomposes and recomposes characters by canonical equivalence.
`NFKC`	Normalization Form Compatibility Composition	Decomposes characters by compatibility, then recomposes them by canonical equivalence.
`NFD`	Normalization Form Canonical Decomposition	Decomposes characters by canonical equivalence, and multiple combining characters are arranged in a specific order.
`NFKD`	Normalization Form Compatibility Decomposition	Decomposes characters by compatibility, and multiple combining characters are arranged in a specific order.

Return type

STRING

Examples

SELECT
  NORMALIZE('The red barn') = NORMALIZE('The Red Barn') AS normalized,
  NORMALIZE_AND_CASEFOLD('The red barn')
    = NORMALIZE_AND_CASEFOLD('The Red Barn') AS normalized_with_case_folding;

/*------------+------------------------------*
 | normalized | normalized_with_case_folding |
 +------------+------------------------------+
 | FALSE      | TRUE                         |
 *------------+------------------------------*/

SELECT
  '\u2168' AS a,
  'IX' AS b,
  NORMALIZE_AND_CASEFOLD('\u2168', NFD)=NORMALIZE_AND_CASEFOLD('IX', NFD) AS nfd,
  NORMALIZE_AND_CASEFOLD('\u2168', NFC)=NORMALIZE_AND_CASEFOLD('IX', NFC) AS nfc,
  NORMALIZE_AND_CASEFOLD('\u2168', NFKD)=NORMALIZE_AND_CASEFOLD('IX', NFKD) AS nkfd,
  NORMALIZE_AND_CASEFOLD('\u2168', NFKC)=NORMALIZE_AND_CASEFOLD('IX', NFKC) AS nkfc;

/*---+----+-------+-------+------+------*
 | a | b  | nfd   | nfc   | nkfd | nkfc |
 +---+----+-------+-------+------+------+
 | Ⅸ | IX | false | false | true | true |
 *---+----+-------+-------+------+------*/

SELECT
  '\u0041\u030A' AS a,
  '\u00C5' AS b,
  NORMALIZE_AND_CASEFOLD('\u0041\u030A', NFD)=NORMALIZE_AND_CASEFOLD('\u00C5', NFD) AS nfd,
  NORMALIZE_AND_CASEFOLD('\u0041\u030A', NFC)=NORMALIZE_AND_CASEFOLD('\u00C5', NFC) AS nfc,
  NORMALIZE_AND_CASEFOLD('\u0041\u030A', NFKD)=NORMALIZE_AND_CASEFOLD('\u00C5', NFKD) AS nkfd,
  NORMALIZE_AND_CASEFOLD('\u0041\u030A', NFKC)=NORMALIZE_AND_CASEFOLD('\u00C5', NFKC) AS nkfc;

/*---+----+-------+-------+------+------*
 | a | b  | nfd   | nfc   | nkfd | nkfc |
 +---+----+-------+-------+------+------+
 | Å | Å  | true  | true  | true | true |
 *---+----+-------+-------+------+------*/

`OCTET_LENGTH`

OCTET_LENGTH(value)

Alias for BYTE_LENGTH.

`REGEXP_CONTAINS`

REGEXP_CONTAINS(value, regexp)

Description

Returns TRUE if value is a partial match for the regular expression, regexp.

If the regexp argument is invalid, the function returns an error.

You can search for a full match by using ^ (beginning of text) and $ (end of text). Due to regular expression operator precedence, it is good practice to use parentheses around everything between ^ and $.

Return type

BOOL

Examples

The following queries check to see if an email is valid:

SELECT
  '[email protected]' AS email,
  REGEXP_CONTAINS('[email protected]', r'@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+') AS is_valid

/*-----------------+----------*
 | email           | is_valid |
 +-----------------+----------+
 | [email protected] | TRUE     |
 *-----------------+----------*/
 ```

 ```sql
SELECT
  'www.example.net' AS email,
  REGEXP_CONTAINS('www.example.net', r'@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+') AS is_valid

/*-----------------+----------*
 | email           | is_valid |
 +-----------------+----------+
 | www.example.net | FALSE    |
 *-----------------+----------*/
 ```

The following queries check to see if an email is valid. They
perform a full match, using `^` and `$`. Due to regular expression operator
precedence, it is good practice to use parentheses around everything between `^`
and `$`.

```sql
SELECT
  '[email protected]' AS email,
  REGEXP_CONTAINS('[email protected]', r'^([\w.+-]+@foo\.com|[\w.+-]+@bar\.org)$') AS valid_email_address,
  REGEXP_CONTAINS('[email protected]', r'^[\w.+-]+@foo\.com|[\w.+-]+@bar\.org$') AS without_parentheses;

/*----------------+---------------------+---------------------*
 | email          | valid_email_address | without_parentheses |
 +----------------+---------------------+---------------------+
 | [email protected]      | true                | true                |
 *----------------+---------------------+---------------------*/

SELECT
  '[email protected]' AS email,
  REGEXP_CONTAINS('[email protected]', r'^([\w.+-]+@foo\.com|[\w.+-]+@bar\.org)$') AS valid_email_address,
  REGEXP_CONTAINS('[email protected]', r'^[\w.+-]+@foo\.com|[\w.+-]+@bar\.org$') AS without_parentheses;

/*----------------+---------------------+---------------------*
 | email          | valid_email_address | without_parentheses |
 +----------------+---------------------+---------------------+
 | [email protected] | false               | true                |
 *----------------+---------------------+---------------------*/

SELECT
  '[email protected]' AS email,
  REGEXP_CONTAINS('[email protected]', r'^([\w.+-]+@foo\.com|[\w.+-]+@bar\.org)$') AS valid_email_address,
  REGEXP_CONTAINS('[email protected]', r'^[\w.+-]+@foo\.com|[\w.+-]+@bar\.org$') AS without_parentheses;

/*----------------+---------------------+---------------------*
 | email          | valid_email_address | without_parentheses |
 +----------------+---------------------+---------------------+
 | [email protected]      | true                | true                |
 *----------------+---------------------+---------------------*/

SELECT
  '[email protected]' AS email,
  REGEXP_CONTAINS('[email protected]', r'^([\w.+-]+@foo\.com|[\w.+-]+@bar\.org)$') AS valid_email_address,
  REGEXP_CONTAINS('[email protected]', r'^[\w.+-]+@foo\.com|[\w.+-]+@bar\.org$') AS without_parentheses;

/*----------------+---------------------+---------------------*
 | email          | valid_email_address | without_parentheses |
 +----------------+---------------------+---------------------+
 | [email protected]     | false               | true                |
 *----------------+---------------------+---------------------*/

SELECT
  '[email protected]' AS email,
  REGEXP_CONTAINS('[email protected]', r'^([\w.+-]+@foo\.com|[\w.+-]+@bar\.org)$') AS valid_email_address,
  REGEXP_CONTAINS('[email protected]', r'^[\w.+-]+@foo\.com|[\w.+-]+@bar\.org$') AS without_parentheses;

/*----------------+---------------------+---------------------*
 | email          | valid_email_address | without_parentheses |
 +----------------+---------------------+---------------------+
 | [email protected]      | false               | false               |
 *----------------+---------------------+---------------------*/

`REGEXP_EXTRACT`

REGEXP_EXTRACT(value, regexp)

Description

Returns the first substring in value that matches the re2 regular expression, regexp. Returns NULL if there is no match.

If the regular expression contains a capturing group ((...)), and there is a match for that capturing group, that match is returned. If there are multiple matches for a capturing group, the first match is returned.

Returns an error if:

The regular expression is invalid
The regular expression has more than one capturing group

Return type

STRING or BYTES

Examples

SELECT REGEXP_EXTRACT('[email protected]', r'^[a-zA-Z0-9_.+-]+') AS user_name

/*-----------*
 | user_name |
 +-----------+
 | foo       |
 *-----------*/

SELECT REGEXP_EXTRACT('[email protected]', r'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.([a-zA-Z0-9-.]+$)')

/*------------------*
 | top_level_domain |
 +------------------+
 | com              |
 *------------------*/

SELECT
  REGEXP_EXTRACT('ab', '.b') AS result_a,
  REGEXP_EXTRACT('ab', '(.)b') AS result_b,
  REGEXP_EXTRACT('xyztb', '(.)+b') AS result_c,
  REGEXP_EXTRACT('ab', '(z)?b') AS result_d

/*-------------------------------------------*
 | result_a | result_b | result_c | result_d |
 +-------------------------------------------+
 | ab       | a        | t        | NULL     |
 *-------------------------------------------*/

`REGEXP_EXTRACT_ALL`

REGEXP_EXTRACT_ALL(value, regexp)

Description

Returns an array of all substrings of value that match the re2 regular expression, regexp. Returns an empty array if there is no match.

If the regular expression contains a capturing group ((...)), and there is a match for that capturing group, that match is added to the results.

The REGEXP_EXTRACT_ALL function only returns non-overlapping matches. For example, using this function to extract ana from banana returns only one substring, not two.

Returns an error if:

The regular expression is invalid
The regular expression has more than one capturing group

Return type

ARRAY<STRING> or ARRAY<BYTES>

Examples

SELECT REGEXP_EXTRACT_ALL('Try `func(x)` or `func(y)`', '`(.+?)`') AS example

/*--------------------*
 | example            |
 +--------------------+
 | [func(x), func(y)] |
 *--------------------*/

`REGEXP_INSTR`

REGEXP_INSTR(source_value, regexp [, position[, occurrence, [occurrence_position]]])

Description

Returns the lowest 1-based position of a regular expression, regexp, in source_value. source_value and regexp must be the same type, either STRING or BYTES.

If position is specified, the search starts at this position in source_value, otherwise it starts at 1, which is the beginning of source_value. position is of type INT64 and must be positive.

If occurrence is specified, the search returns the position of a specific instance of regexp in source_value. If not specified, occurrence defaults to 1 and returns the position of the first occurrence. For occurrence > 1, the function searches for the next, non-overlapping occurrence. occurrence is of type INT64 and must be positive.

You can optionally use occurrence_position to specify where a position in relation to an occurrence starts. Your choices are:

0: Returns the start position of occurrence.
1: Returns the end position of occurrence + 1. If the end of the occurrence is at the end of source_value, LENGTH(source_value) + 1 is returned.

Returns 0 if:

No match is found.
If occurrence is greater than the number of matches found.
If position is greater than the length of source_value.
The regular expression is empty.

Returns NULL if:

position is NULL.
occurrence is NULL.

Returns an error if:

position is 0 or negative.
occurrence is 0 or negative.
occurrence_position is neither 0 nor 1.
The regular expression is invalid.
The regular expression has more than one capturing group.

Return type

INT64

Examples

SELECT
  REGEXP_INSTR('ab@cd-ef',  '@[^-]*') AS instr_a,
  REGEXP_INSTR('ab@d-ef',   '@[^-]*') AS instr_b,
  REGEXP_INSTR('abc@cd-ef', '@[^-]*') AS instr_c,
  REGEXP_INSTR('abc-ef',    '@[^-]*') AS instr_d,

/*---------------------------------------*
 | instr_a | instr_b | instr_c | instr_d |
 +---------------------------------------+
 | 3       | 3       | 4       | 0       |
 *---------------------------------------*/

SELECT
  REGEXP_INSTR('a@cd-ef b@cd-ef', '@[^-]*', 1) AS instr_a,
  REGEXP_INSTR('a@cd-ef b@cd-ef', '@[^-]*', 2) AS instr_b,
  REGEXP_INSTR('a@cd-ef b@cd-ef', '@[^-]*', 3) AS instr_c,
  REGEXP_INSTR('a@cd-ef b@cd-ef', '@[^-]*', 4) AS instr_d,

/*---------------------------------------*
 | instr_a | instr_b | instr_c | instr_d |
 +---------------------------------------+
 | 2       | 2       | 10      | 10      |
 *---------------------------------------*/

SELECT
  REGEXP_INSTR('a@cd-ef b@cd-ef c@cd-ef', '@[^-]*', 1, 1) AS instr_a,
  REGEXP_INSTR('a@cd-ef b@cd-ef c@cd-ef', '@[^-]*', 1, 2) AS instr_b,
  REGEXP_INSTR('a@cd-ef b@cd-ef c@cd-ef', '@[^-]*', 1, 3) AS instr_c

/*-----------------------------*
 | instr_a | instr_b | instr_c |
 +-----------------------------+
 | 2       | 10      | 18      |
 *-----------------------------*/

SELECT
  REGEXP_INSTR('a@cd-ef', '@[^-]*', 1, 1, 0) AS instr_a,
  REGEXP_INSTR('a@cd-ef', '@[^-]*', 1, 1, 1) AS instr_b

/*-------------------*
 | instr_a | instr_b |
 +-------------------+
 | 2       | 5       |
 *-------------------*/

`REGEXP_REPLACE`

REGEXP_REPLACE(value, regexp, replacement)

Description

Returns a STRING where all substrings of value that match regular expression regexp are replaced with replacement.

You can use backslashed-escaped digits (\1 to \9) within the replacement argument to insert text matching the corresponding parenthesized group in the regexp pattern. Use \0 to refer to the entire matching text.

To add a backslash in your regular expression, you must first escape it. For example, SELECT REGEXP_REPLACE('abc', 'b(.)', 'X\\1'); returns aXc. You can also use raw strings to remove one layer of escaping, for example SELECT REGEXP_REPLACE('abc', 'b(.)', r'X\1');.

The REGEXP_REPLACE function only replaces non-overlapping matches. For example, replacing ana within banana results in only one replacement, not two.

If the regexp argument is not a valid regular expression, this function returns an error.

Return type

STRING or BYTES

Examples

SELECT REGEXP_REPLACE('# Heading', r'^# ([a-zA-Z0-9\s]+$)', '<h1>\\1</h1>') AS html

/*--------------------------*
 | html                     |
 +--------------------------+
 | <h1>Heading</h1>         |
 *--------------------------*/

`REPEAT`

REPEAT(original_value, repetitions)

Description

Returns a STRING or BYTES value that consists of original_value, repeated. The repetitions parameter specifies the number of times to repeat original_value. Returns NULL if either original_value or repetitions are NULL.

This function returns an error if the repetitions value is negative.

Return type

STRING or BYTES

Examples

SELECT REPEAT('abc', 3) AS results

/*-----------*
 | results   |
 |-----------|
 | abcabcabc |
 *-----------*/

SELECT REPEAT('abc', NULL) AS results

/*---------*
 | results |
 |---------|
 | NULL    |
 *---------*/

SELECT REPEAT(NULL, 3) AS results

/*---------*
 | results |
 |---------|
 | NULL    |
 *---------*/

`REPLACE`

REPLACE(original_value, from_pattern, to_pattern)

Description

Replaces all occurrences of from_pattern with to_pattern in original_value. If from_pattern is empty, no replacement is made.

This function supports specifying collation.

Return type

STRING or BYTES

Examples

`REVERSE`

REVERSE(value)

Description

Returns the reverse of the input STRING or BYTES.

Return type

STRING or BYTES

Examples

SELECT REVERSE('abc') AS results

/*---------*
 | results |
 +---------+
 | cba     |
 *---------*/

SELECT FORMAT('%T', REVERSE(b'1a3')) AS results

/*---------*
 | results |
 +---------+
 | b"3a1"  |
 *---------*/

`RIGHT`

RIGHT(value, length)

Description

Returns a STRING or BYTES value that consists of the specified number of rightmost characters or bytes from value. The length is an INT64 that specifies the length of the returned value. If value is BYTES, length is the number of rightmost bytes to return. If value is STRING, length is the number of rightmost characters to return.

Return type

STRING or BYTES

Examples

SELECT 'apple' AS example, RIGHT('apple', 3) AS right_example

/*---------+---------------*
 | example | right_example |
 +---------+---------------+
 | apple   | ple           |
 *---------+---------------*/

SELECT b'apple' AS example, RIGHT(b'apple', 3) AS right_example

-- Note that the result of RIGHT is of type BYTES, displayed as a base64-encoded string.
/*----------+---------------*
 | example  | right_example |
 +----------+---------------+
 | YXBwbGU= | cGxl          |
 *----------+---------------*/

`RPAD`

RPAD(original_value, return_length[, pattern])

Description

Returns a STRING or BYTES value that consists of original_value appended with pattern. The return_length parameter is an INT64 that specifies the length of the returned value. If original_value is BYTES, return_length is the number of bytes. If original_value is STRING, return_length is the number of characters.

The default value of pattern is a blank space.

Both original_value and pattern must be the same data type.

If original_value, return_length, or pattern is NULL, this function returns NULL.

This function returns an error if:

return_length is negative
pattern is empty

Return type

STRING or BYTES

Examples

SELECT FORMAT('%T', RPAD('c', 5)) AS results

/*---------*
 | results |
 +---------+
 | "c    " |
 *---------*/

SELECT RPAD('b', 5, 'a') AS results

/*---------*
 | results |
 +---------+
 | baaaa   |
 *---------*/

SELECT RPAD('abc', 10, 'ghd') AS results

/*------------*
 | results    |
 +------------+
 | abcghdghdg |
 *------------*/

SELECT RPAD('abc', 2, 'd') AS results

/*---------*
 | results |
 +---------+
 | ab      |
 *---------*/

SELECT FORMAT('%T', RPAD(b'abc', 10, b'ghd')) AS results

/*---------------*
 | results       |
 +---------------+
 | b"abcghdghdg" |
 *---------------*/

`RTRIM`

RTRIM(value1[, value2])

Description

Identical to TRIM, but only removes trailing characters.

Return type

STRING or BYTES

Examples

SELECT RTRIM('***apple***', '*') AS example

/*-----------*
 | example   |
 +-----------+
 | ***apple  |
 *-----------*/

SELECT RTRIM('applexxz', 'xyz') AS example

/*---------*
 | example |
 +---------+
 | apple   |
 *---------*/

`SAFE_CONVERT_BYTES_TO_STRING`

SAFE_CONVERT_BYTES_TO_STRING(value)

Description

Converts a sequence of BYTES to a STRING. Any invalid UTF-8 characters are replaced with the Unicode replacement character, U+FFFD.

Return type

STRING

Examples

The following statement returns the Unicode replacement character, �.

SELECT SAFE_CONVERT_BYTES_TO_STRING(b'\xc2') as safe_convert;

`SOUNDEX`

SOUNDEX(value)

Description

Returns a STRING that represents the Soundex code for value.

SOUNDEX produces a phonetic representation of a string. It indexes words by sound, as pronounced in English. It is typically used to help determine whether two strings, such as the family names Levine and Lavine, or the words to and too, have similar English-language pronunciation.

The result of the SOUNDEX consists of a letter followed by 3 digits. Non-latin characters are ignored. If the remaining string is empty after removing non-Latin characters, an empty STRING is returned.

Return type

STRING

Examples

SELECT 'Ashcraft' AS value, SOUNDEX('Ashcraft') AS soundex

/*----------------------+---------*
 | value                | soundex |
 +----------------------+---------+
 | Ashcraft             | A261    |
 *----------------------+---------*/

`SPLIT`

SPLIT(value[, delimiter])

Description

Splits a STRING or BYTES value, using a delimiter. The delimiter argument must be a literal character or sequence of characters. You can't split with a regular expression.

For STRING, the default delimiter is the comma ,.

For BYTES, you must specify a delimiter.

Splitting on an empty delimiter produces an array of UTF-8 characters for STRING values, and an array of BYTES for BYTES values.

Splitting an empty STRING returns an ARRAY with a single empty STRING.

This function supports specifying collation.

Return type

ARRAY<STRING> or ARRAY<BYTES>

Examples

`STARTS_WITH`

STARTS_WITH(value, prefix)

Description

Takes two STRING or BYTES values. Returns TRUE if prefix is a prefix of value.

This function supports specifying collation.

Return type

BOOL

Examples

SELECT STARTS_WITH('bar', 'b') AS example

/*---------*
 | example |
 +---------+
 |    True |
 *---------*/

`STRPOS`

STRPOS(value, subvalue)

Description

Takes two STRING or BYTES values. Returns the 1-based position of the first occurrence of subvalue inside value. Returns 0 if subvalue is not found.

This function supports specifying collation.

Return type

INT64

Examples

SELECT STRPOS('[email protected]', '@') AS example

/*---------*
 | example |
 +---------+
 |       4 |
 *---------*/

`SUBSTR`

SUBSTR(value, position[, length])

Description

Gets a portion (substring) of the supplied STRING or BYTES value.

The position argument is an integer specifying the starting position of the substring.

If position is 1, the substring starts from the first character or byte.
If position is 0 or less than -LENGTH(value), position is set to 1, and the substring starts from the first character or byte.
If position is greater than the length of value, the function produces an empty substring.
If position is negative, the function counts from the end of value, with -1 indicating the last character or byte.

The length argument specifies the maximum number of characters or bytes to return.

If length is not specified, the function produces a substring that starts at the specified position and ends at the last character or byte of value.
If length is 0, the function produces an empty substring.
If length is negative, the function produces an error.
The returned substring may be shorter than length, for example, when length exceeds the length of value, or when the starting position of the substring plus length is greater than the length of value.

Return type

STRING or BYTES

Examples

SELECT SUBSTR('apple', 2) AS example

/*---------*
 | example |
 +---------+
 | pple    |
 *---------*/

SELECT SUBSTR('apple', 2, 2) AS example

/*---------*
 | example |
 +---------+
 | pp      |
 *---------*/

SELECT SUBSTR('apple', -2) AS example

/*---------*
 | example |
 +---------+
 | le      |
 *---------*/

SELECT SUBSTR('apple', 1, 123) AS example

/*---------*
 | example |
 +---------+
 | apple   |
 *---------*/

SELECT SUBSTR('apple', 123) AS example

/*---------*
 | example |
 +---------+
 |         |
 *---------*/

SELECT SUBSTR('apple', 123, 5) AS example

/*---------*
 | example |
 +---------+
 |         |
 *---------*/

`SUBSTRING`

SUBSTRING(value, position[, length])

Alias for SUBSTR.

`TO_BASE32`

TO_BASE32(bytes_expr)

Description

Converts a sequence of BYTES into a base32-encoded STRING. To convert a base32-encoded STRING into BYTES, use FROM_BASE32.

Return type

STRING

Example

SELECT TO_BASE32(b'abcde\xFF') AS base32_string;

/*------------------*
 | base32_string    |
 +------------------+
 | MFRGGZDF74====== |
 *------------------*/

`TO_BASE64`

TO_BASE64(bytes_expr)

Description

Converts a sequence of BYTES into a base64-encoded STRING. To convert a base64-encoded STRING into BYTES, use FROM_BASE64.

Return type

STRING

Example

SELECT TO_BASE64(b'\377\340') AS base64_string;

/*---------------*
 | base64_string |
 +---------------+
 | /+A=          |
 *---------------*/

To work with an encoding using a different base64 alphabet, you might need to compose TO_BASE64 with the REPLACE function. For instance, the base64url url-safe and filename-safe encoding commonly used in web programming uses -_= as the last characters rather than +/=. To encode a base64url-encoded string, replace + and / with - and _ respectively.

SELECT REPLACE(REPLACE(TO_BASE64(b'\377\340'), '+', '-'), '/', '_') as websafe_base64;

/*----------------*
 | websafe_base64 |
 +----------------+
 | _-A=           |
 *----------------*/

`TO_CODE_POINTS`

TO_CODE_POINTS(value)

Description

Takes a STRING or BYTES value and returns an array of INT64 values that represent code points or extended ASCII character values.

If value is a STRING, each element in the returned array represents a code point. Each code point falls within the range of [0, 0xD7FF] and [0xE000, 0x10FFFF].
If value is BYTES, each element in the array is an extended ASCII character value in the range of [0, 255].

To convert from an array of code points to a STRING or BYTES, see CODE_POINTS_TO_STRING or CODE_POINTS_TO_BYTES.

Return type

ARRAY<INT64>

Examples

The following examples get the code points for each element in an array of words.

SELECT
  'foo' AS word,
  TO_CODE_POINTS('foo') AS code_points

/*---------+------------------------------------*
 | word    | code_points                        |
 +---------+------------------------------------+
 | foo     | [102, 111, 111]                    |
 *---------+------------------------------------*/

SELECT
  'bar' AS word,
  TO_CODE_POINTS('bar') AS code_points

/*---------+------------------------------------*
 | word    | code_points                        |
 +---------+------------------------------------+
 | bar     | [98, 97, 114]                      |
 *---------+------------------------------------*/

SELECT
  'baz' AS word,
  TO_CODE_POINTS('baz') AS code_points

/*---------+------------------------------------*
 | word    | code_points                        |
 +---------+------------------------------------+
 | baz     | [98, 97, 122]                      |
 *---------+------------------------------------*/

SELECT
  'giraffe' AS word,
  TO_CODE_POINTS('giraffe') AS code_points

/*---------+------------------------------------*
 | word    | code_points                        |
 +---------+------------------------------------+
 | giraffe | [103, 105, 114, 97, 102, 102, 101] |
 *---------+------------------------------------*/

SELECT
  'llama' AS word,
  TO_CODE_POINTS('llama') AS code_points

/*---------+------------------------------------*
 | word    | code_points                        |
 +---------+------------------------------------+
 | llama   | [108, 108, 97, 109, 97]            |
 *---------+------------------------------------*/

The following examples convert integer representations of BYTES to their corresponding ASCII character values.

SELECT
  b'\x66\x6f\x6f' AS bytes_value,
  TO_CODE_POINTS(b'\x66\x6f\x6f') AS bytes_value_as_integer

/*------------------+------------------------*
 | bytes_value      | bytes_value_as_integer |
 +------------------+------------------------+
 | foo              | [102, 111, 111]        |
 *------------------+------------------------*/

SELECT
  b'\x00\x01\x10\xff' AS bytes_value,
  TO_CODE_POINTS(b'\x00\x01\x10\xff') AS bytes_value_as_integer

/*------------------+------------------------*
 | bytes_value      | bytes_value_as_integer |
 +------------------+------------------------+
 | \x00\x01\x10\xff | [0, 1, 16, 255]        |
 *------------------+------------------------*/

The following example demonstrates the difference between a BYTES result and a STRING result. Notice that the character Ā is represented as a two-byte Unicode sequence. As a result, the BYTES version of TO_CODE_POINTS returns an array with two elements, while the STRING version returns an array with a single element.

SELECT TO_CODE_POINTS(b'Ā') AS b_result, TO_CODE_POINTS('Ā') AS s_result;

/*------------+----------*
 | b_result   | s_result |
 +------------+----------+
 | [196, 128] | [256]    |
 *------------+----------*/

`TO_HEX`

TO_HEX(bytes)

Description

Converts a sequence of BYTES into a hexadecimal STRING. Converts each byte in the STRING as two hexadecimal characters in the range (0..9, a..f). To convert a hexadecimal-encoded STRING to BYTES, use FROM_HEX.

Return type

STRING

Example

SELECT
  b'\x00\x01\x02\x03\xAA\xEE\xEF\xFF' AS byte_string,
  TO_HEX(b'\x00\x01\x02\x03\xAA\xEE\xEF\xFF') AS hex_string

/*----------------------------------+------------------*
 | byte_string                      | hex_string       |
 +----------------------------------+------------------+
 | \x00\x01\x02\x03\xaa\xee\xef\xff | 00010203aaeeefff |
 *----------------------------------+------------------*/

`TO_INT64`

TO_INT64(bytes_value)

Description

Converts the big-endian bytes of a 64-bit signed integer into an INT64 value.

Definitions

bytes_value: The big-endian bytes to convert. The length of bytes_value must be 8. If NULL, the function returns NULL.

Return Data Type

INT64

Example

SELECT TO_INT64(b'\x00\x00\x00\x00\x00\x00\x00d') AS integer_value

/*---------------------*
 | integer_value       |
 +---------------------+
 | 100                 |
 *---------------------*/

`TO_VECTOR32`

TO_VECTOR32(bytes_value)

Description

Converts the big-endian bytes of one or more 32-bit IEEE 754 floating point numbers into an ARRAY value.

Definitions

bytes_value: The bytes to convert, which must be the concatenation of the big-endian bytes of 32-bit IEEE 754 floating point numbers. The length of bytes_value must be a multiple of 8. If NULL, the function returns NULL.

Return Data Type

ARRAY<FLOAT32>

Example

SELECT TO_VECTOR32(b'\x3f\xc0\x00\x00\x42\xc8\x00\x00') AS array_val

/*---------------------*
 | array_val           |
 +---------------------+
 | [ 1.5, 100.0 ]      |
 *---------------------*/

`TO_VECTOR64`

TO_VECTOR64(bytes_value)

Description

Converts the big-endian bytes of one or more 64-bit IEEE 754 floating point numbers into an ARRAY value.

Definitions

bytes_value: The bytes to convert, which must be the concatenation of the big-endian bytes of 64-bit IEEE 754 floating point numbers. The length of bytes_value must be a multiple of 8. If NULL, the function returns NULL.

Return Data Type

ARRAY<FLOAT64>

Example

SELECT TO_VECTOR64(b'\x40\x5e\xdc\xcc\xcc\xcc\xcc\xcd\x40\x4c\x63\xd7\x0a\x3d\x70\xa4') AS array_val

/*---------------------*
 | array_val           |
 +---------------------+
 | [ 123.45, 56.78 ]   |
 *---------------------*/

`TRANSLATE`

TRANSLATE(expression, source_characters, target_characters)

Description

In expression, replaces each character in source_characters with the corresponding character in target_characters. All inputs must be the same type, either STRING or BYTES.

Each character in expression is translated at most once.
A character in expression that is not present in source_characters is left unchanged in expression.
A character in source_characters without a corresponding character in target_characters is omitted from the result.
A duplicate character in source_characters results in an error.

Return type

STRING or BYTES

Examples

SELECT TRANSLATE('This is a cookie', 'sco', 'zku') AS translate

/*------------------*
 | translate        |
 +------------------+
 | Thiz iz a kuukie |
 *------------------*/

`TRIM`

TRIM(value_to_trim[, set_of_characters_to_remove])

Description

Takes a STRING or BYTES value to trim.

If the value to trim is a STRING, removes from this value all leading and trailing Unicode code points in set_of_characters_to_remove. The set of code points is optional. If it is not specified, all whitespace characters are removed from the beginning and end of the value to trim.

If the value to trim is BYTES, removes from this value all leading and trailing bytes in set_of_characters_to_remove. The set of bytes is required.

Return type

STRING if value_to_trim is a STRING value.
BYTES if value_to_trim is a BYTES value.

Examples

In the following example, all leading and trailing whitespace characters are removed from item because set_of_characters_to_remove is not specified.

SELECT CONCAT('#', TRIM( '   apple   '), '#') AS example

/*----------*
 | example  |
 +----------+
 | #apple#  |
 *----------*/

In the following example, all leading and trailing * characters are removed from 'apple'.

SELECT TRIM('***apple***', '*') AS example

/*---------*
 | example |
 +---------+
 | apple   |
 *---------*/

In the following example, all leading and trailing x, y, and z characters are removed from 'xzxapplexxy'.

SELECT TRIM('xzxapplexxy', 'xyz') as example

/*---------*
 | example |
 +---------+
 | apple   |
 *---------*/

In the following example, examine how TRIM interprets characters as Unicode code-points. If your trailing character set contains a combining diacritic mark over a particular letter, TRIM might strip the same diacritic mark from a different letter.

SELECT
  TRIM('abaW̊', 'Y̊') AS a,
  TRIM('W̊aba', 'Y̊') AS b,
  TRIM('abaŪ̊', 'Y̊') AS c,
  TRIM('Ū̊aba', 'Y̊') AS d

/*------+------+------+------*
 | a    | b    | c    | d    |
 +------+------+------+------+
 | abaW | W̊aba | abaŪ | Ūaba |
 *------+------+------+------*/

In the following example, all leading and trailing b'n', b'a', b'\xab' bytes are removed from item.

SELECT b'apple', TRIM(b'apple', b'na\xab') AS example

-- Note that the result of TRIM is of type BYTES, displayed as a base64-encoded string.
/*----------------------+------------------*
 | item                 | example          |
 +----------------------+------------------+
 | YXBwbGU=             | cHBsZQ==         |
 *----------------------+------------------*/

`UNICODE`

UNICODE(value)

Description

Returns the Unicode code point for the first character in value. Returns 0 if value is empty, or if the resulting Unicode code point is 0.

Return type

INT64

Examples

SELECT UNICODE('âbcd') as A, UNICODE('â') as B, UNICODE('') as C, UNICODE(NULL) as D;

/*-------+-------+-------+-------*
 | A     | B     | C     | D     |
 +-------+-------+-------+-------+
 | 226   | 226   | 0     | NULL  |
 *-------+-------+-------+-------*/

`UPPER`

UPPER(value)

Description

For STRING arguments, returns the original string with all alphabetic characters in uppercase. Mapping between uppercase and lowercase is done according to the Unicode Character Database without taking into account language-specific mappings.

For BYTES arguments, the argument is treated as ASCII text, with all bytes greater than 127 left intact.

Return type

STRING or BYTES

Examples

SELECT UPPER('foo') AS example

/*---------*
 | example |
 +---------+
 | FOO     |
 *---------*/