Operators

GoogleSQL for BigQuery supports operators. Operators are represented by special characters or keywords; they don't use function call syntax. An operator manipulates any number of data inputs, also called operands, and returns a result.

Common conventions:

• Unless otherwise specified, all operators return NULL when one of the operands is NULL.
• All operators will throw an error if the computation result overflows.
• For all floating point operations, +/-inf and NaN may only be returned if one of the operands is +/-inf or NaN. In other cases, an error is returned.

Operator precedence

The following table lists all GoogleSQL operators from highest to lowest precedence, i.e., the order in which they will be evaluated within a statement.

For example, the logical expression:

x OR y AND z

is interpreted as:

( x OR ( y AND z ) )

Operators with the same precedence are left associative. This means that those operators are grouped together starting from the left and moving right. For example, the expression:

x AND y AND z

is interpreted as:

( ( x AND y ) AND z )

The expression:

x * y / z

is interpreted as:

( ( x * y ) / z )

All comparison operators have the same priority, but comparison operators aren't associative. Therefore, parentheses are required to resolve ambiguity. For example:

(x < y) IS FALSE

Operator list

Field access operator

expression.fieldname[. ...] 

Description

Gets the value of a field. Alternatively known as the dot operator. Can be used to access nested fields. For example, expression.fieldname1.fieldname2.

Input values:

• STRUCT
• JSON

Return type

• For STRUCT: SQL data type of fieldname. If a field isn't found in the struct, an error is thrown.
• For JSON: JSON. If a field isn't found in a JSON value, a SQL NULL is returned.

Example

In the following example, the field access operations are .address and .country.

SELECT   STRUCT(     STRUCT('Yonge Street' AS street, 'Canada' AS country)       AS address).address.country  /*---------+  | country |  +---------+  | Canada  |  +---------*/ 

Array subscript operator

array_expression "[" array_subscript_specifier "]"  array_subscript_specifier:   { index | position_keyword(index) }  position_keyword:   { OFFSET | SAFE_OFFSET | ORDINAL | SAFE_ORDINAL } 

Description

Gets a value from an array at a specific position.

Input values:

• array_expression: The input array.
• position_keyword(index): Determines where the index for the array should start and how out-of-range indexes are handled. The index is an integer that represents a specific position in the array.
  • OFFSET(index): The index starts at zero. Produces an error if the index is out of range. To produce NULL instead of an error, use SAFE_OFFSET(index). This position keyword produces the same result as index by itself.
  • SAFE_OFFSET(index): The index starts at zero. Returns NULL if the index is out of range.
  • ORDINAL(index): The index starts at one. Produces an error if the index is out of range. To produce NULL instead of an error, use SAFE_ORDINAL(index).
  • SAFE_ORDINAL(index): The index starts at one. Returns NULL if the index is out of range.
• index: An integer that represents a specific position in the array. If used by itself without a position keyword, the index starts at zero and produces an error if the index is out of range. To produce NULL instead of an error, use the SAFE_OFFSET(index) or SAFE_ORDINAL(index) position keyword.

Return type

T where array_expression is ARRAY<T>.

Examples

In following query, the array subscript operator is used to return values at specific position in item_array. This query also shows what happens when you reference an index (6) in an array that's out of range. If the SAFE prefix is included, NULL is returned, otherwise an error is produced.

SELECT   ["coffee", "tea", "milk"] AS item_array,   ["coffee", "tea", "milk"][0] AS item_index,   ["coffee", "tea", "milk"][OFFSET(0)] AS item_offset,   ["coffee", "tea", "milk"][ORDINAL(1)] AS item_ordinal,   ["coffee", "tea", "milk"][SAFE_OFFSET(6)] AS item_safe_offset  /*---------------------+------------+-------------+--------------+------------------+  | item_array          | item_index | item_offset | item_ordinal | item_safe_offset |  +---------------------+------------+-------------+--------------+------------------+  | [coffee, tea, milk] | coffee     | coffee      | coffee       | NULL             |  +----------------------------------+-------------+--------------+------------------*/ 

When you reference an index that's out of range in an array, and a positional keyword that begins with SAFE isn't included, an error is produced. For example:

-- Error. Array index 6 is out of bounds. SELECT ["coffee", "tea", "milk"][6] AS item_offset 

-- Error. Array index 6 is out of bounds. SELECT ["coffee", "tea", "milk"][OFFSET(6)] AS item_offset 

Struct subscript operator

struct_expression "[" struct_subscript_specifier "]"  struct_subscript_specifier:   { index | position_keyword(index) }  position_keyword:   { OFFSET | ORDINAL } 

Description

Gets the value of a field at a selected position in a struct.

Input types

• struct_expression: The input struct.
• position_keyword(index): Determines where the index for the struct should start and how out-of-range indexes are handled. The index is an integer literal or constant that represents a specific position in the struct.
  • OFFSET(index): The index starts at zero. Produces an error if the index is out of range. Produces the same result as index by itself.
  • ORDINAL(index): The index starts at one. Produces an error if the index is out of range.
• index: An integer literal or constant that represents a specific position in the struct. If used by itself without a position keyword, the index starts at zero and produces an error if the index is out of range.

Examples

In following query, the struct subscript operator is used to return values at specific locations in item_struct using position keywords. This query also shows what happens when you reference an index (6) in an struct that's out of range.

SELECT   STRUCT<INT64, STRING, BOOL>(23, "tea", FALSE)[0] AS field_index,   STRUCT<INT64, STRING, BOOL>(23, "tea", FALSE)[OFFSET(0)] AS field_offset,   STRUCT<INT64, STRING, BOOL>(23, "tea", FALSE)[ORDINAL(1)] AS field_ordinal  /*-------------+--------------+---------------+  | field_index | field_offset | field_ordinal |  +-------------+--------------+---------------+  | 23          | 23           | 23            |  +-------------+--------------+---------------*/ 

When you reference an index that's out of range in a struct, an error is produced. For example:

-- Error: Field ordinal 6 is out of bounds in STRUCT SELECT STRUCT<INT64, STRING, BOOL>(23, "tea", FALSE)[6] AS field_offset 

-- Error: Field ordinal 6 is out of bounds in STRUCT SELECT STRUCT<INT64, STRING, BOOL>(23, "tea", FALSE)[OFFSET(6)] AS field_offset 

JSON subscript operator

json_expression "[" array_element_id "]" 

json_expression "[" field_name "]" 

Description

Gets a value of an array element or field in a JSON expression. Can be used to access nested data.

Input values:

• JSON expression: The JSON expression that contains an array element or field to return.
• [array_element_id]: An INT64 expression that represents a zero-based index in the array. If a negative value is entered, or the value is greater than or equal to the size of the array, or the JSON expression doesn't represent a JSON array, a SQL NULL is returned.
• [field_name]: A STRING expression that represents the name of a field in JSON. If the field name isn't found, or the JSON expression isn't a JSON object, a SQL NULL is returned.

Return type

JSON

Example

In the following example:

• json_value is a JSON expression.
• .class is a JSON field access.
• .students is a JSON field access.
• [0] is a JSON subscript expression with an element offset that accesses the zeroth element of an array in the JSON value.
• ['name'] is a JSON subscript expression with a field name that accesses a field.

SELECT json_value.class.students[0]['name'] AS first_student FROM   UNNEST(     [       JSON '{"class" : {"students" : [{"name" : "Jane"}]}}',       JSON '{"class" : {"students" : []}}',       JSON '{"class" : {"students" : [{"name" : "John"}, {"name": "Jamie"}]}}'])     AS json_value;  /*-----------------+  | first_student   |  +-----------------+  | "Jane"          |  | NULL            |  | "John"          |  +-----------------*/ 

Arithmetic operators

All arithmetic operators accept input of numeric type T, and the result type has type T unless otherwise indicated in the description below:

NOTE: Divide by zero operations return an error. To return a different result, consider the IEEE_DIVIDE or SAFE_DIVIDE functions.

Result types for Addition, Subtraction and Multiplication:

Result types for Division:

Result types for Unary Plus:

Result types for Unary Minus:

Date arithmetics operators

Operators '+' and '-' can be used for arithmetic operations on dates.

date_expression + int64_expression int64_expression + date_expression date_expression - int64_expression 

Description

Adds or subtracts int64_expression days to or from date_expression. This is equivalent to DATE_ADD or DATE_SUB functions, when interval is expressed in days.

Return Data Type

DATE

Example

SELECT DATE "2020-09-22" + 1 AS day_later, DATE "2020-09-22" - 7 AS week_ago  /*------------+------------+  | day_later  | week_ago   |  +------------+------------+  | 2020-09-23 | 2020-09-15 |  +------------+------------*/ 

Datetime subtraction

date_expression - date_expression timestamp_expression - timestamp_expression datetime_expression - datetime_expression 

Description

Computes the difference between two datetime values as an interval.

Return Data Type

INTERVAL

Example

SELECT   DATE "2021-05-20" - DATE "2020-04-19" AS date_diff,   TIMESTAMP "2021-06-01 12:34:56.789" - TIMESTAMP "2021-05-31 00:00:00" AS time_diff  /*-------------------+------------------------+  | date_diff         | time_diff              |  +-------------------+------------------------+  | 0-0 396 0:0:0     | 0-0 0 36:34:56.789     |  +-------------------+------------------------*/ 

Interval arithmetic operators

Addition and subtraction

date_expression + interval_expression = DATETIME date_expression - interval_expression = DATETIME timestamp_expression + interval_expression = TIMESTAMP timestamp_expression - interval_expression = TIMESTAMP datetime_expression + interval_expression = DATETIME datetime_expression - interval_expression = DATETIME  

Description

Adds an interval to a datetime value or subtracts an interval from a datetime value.

Example

SELECT   DATE "2021-04-20" + INTERVAL 25 HOUR AS date_plus,   TIMESTAMP "2021-05-02 00:01:02.345" - INTERVAL 10 SECOND AS time_minus;  /*-------------------------+--------------------------------+  | date_plus               | time_minus                     |  +-------------------------+--------------------------------+  | 2021-04-21 01:00:00     | 2021-05-02 00:00:52.345+00     |  +-------------------------+--------------------------------*/ 

Multiplication and division

interval_expression * integer_expression = INTERVAL interval_expression / integer_expression = INTERVAL  

Description

Multiplies or divides an interval value by an integer.

Example

SELECT   INTERVAL '1:2:3' HOUR TO SECOND * 10 AS mul1,   INTERVAL 35 SECOND * 4 AS mul2,   INTERVAL 10 YEAR / 3 AS div1,   INTERVAL 1 MONTH / 12 AS div2  /*----------------+--------------+-------------+--------------+  | mul1           | mul2         | div1        | div2         |  +----------------+--------------+-------------+--------------+  | 0-0 0 10:20:30 | 0-0 0 0:2:20 | 3-4 0 0:0:0 | 0-0 2 12:0:0 |  +----------------+--------------+-------------+--------------*/ 

Bitwise operators

All bitwise operators return the same type and the same length as the first operand.

Logical operators

GoogleSQL supports the AND, OR, and NOT logical operators. Logical operators allow only BOOL or NULL input and use three-valued logic to produce a result. The result can be TRUE, FALSE, or NULL:

The order of evaluation of operands to AND and OR can vary, and evaluation can be skipped if unnecessary.

Examples

The examples in this section reference a table called entry_table:

/*-------+  | entry |  +-------+  | a     |  | b     |  | c     |  | NULL  |  +-------*/ 

SELECT 'a' FROM entry_table WHERE entry = 'a'  -- a => 'a' = 'a' => TRUE -- b => 'b' = 'a' => FALSE -- NULL => NULL = 'a' => NULL  /*-------+  | entry |  +-------+  | a     |  +-------*/ 

SELECT entry FROM entry_table WHERE NOT (entry = 'a')  -- a => NOT('a' = 'a') => NOT(TRUE) => FALSE -- b => NOT('b' = 'a') => NOT(FALSE) => TRUE -- NULL => NOT(NULL = 'a') => NOT(NULL) => NULL  /*-------+  | entry |  +-------+  | b     |  | c     |  +-------*/ 

SELECT entry FROM entry_table WHERE entry IS NULL  -- a => 'a' IS NULL => FALSE -- b => 'b' IS NULL => FALSE -- NULL => NULL IS NULL => TRUE  /*-------+  | entry |  +-------+  | NULL  |  +-------*/ 

Comparison operators

Compares operands and produces the results of the comparison as a BOOL value. These comparison operators are available:

The following rules apply to operands in a comparison operator:

• The operands must be comparable.
• A comparison operator generally requires both operands to be of the same type.
• If the operands are of different types, and the values of those types can be converted to a common type without loss of precision, they are generally coerced to that common type for the comparison.
• A literal operand is generally coerced to the same data type of a non-literal operand that's part of the comparison.
• Struct operands support only these comparison operators: equal (=), not equal (!= and <>), and IN.

The following rules apply when comparing these data types:

• FLOAT64: All comparisons with NaN return FALSE, except for != and <>, which return TRUE.
• BOOL: FALSE is less than TRUE.
• STRING: Strings are compared codepoint-by-codepoint, which means that canonically equivalent strings are only guaranteed to compare as equal if they have been normalized first.
• JSON: You can't compare JSON, but you can compare the values inside of JSON if you convert the values to SQL values first. For more information, see JSON functions.
• NULL: Any operation with a NULL input returns NULL.

• STRUCT: When testing a struct for equality, it's possible that one or more fields are NULL. In such cases:

  • If all non-NULL field values are equal, the comparison returns NULL.
  • If any non-NULL field values aren't equal, the comparison returns FALSE.

  The following table demonstrates how STRUCT data types are compared when they have fields that are NULL valued.

  Struct1	Struct2	Struct1 = Struct2
  STRUCT(1, NULL)	STRUCT(1, NULL)	NULL
  STRUCT(1, NULL)	STRUCT(2, NULL)	FALSE
  STRUCT(1,2)	STRUCT(1, NULL)	NULL

EXISTS operator

EXISTS( subquery ) 

Description

Returns TRUE if the subquery produces one or more rows. Returns FALSE if the subquery produces zero rows. Never returns NULL. To learn more about how you can use a subquery with EXISTS, see EXISTS subqueries.

Examples

In this example, the EXISTS operator returns FALSE because there are no rows in Words where the direction is south:

WITH Words AS (   SELECT 'Intend' as value, 'east' as direction UNION ALL   SELECT 'Secure', 'north' UNION ALL   SELECT 'Clarity', 'west'  ) SELECT EXISTS( SELECT value FROM Words WHERE direction = 'south' ) as result;  /*--------+  | result |  +--------+  | FALSE  |  +--------*/ 

IN operator

The IN operator supports the following syntax:

search_value [NOT] IN value_set  value_set:   {     (expression[, ...])     | (subquery)     | UNNEST(array_expression)   } 

Description

Checks for an equal value in a set of values. Semantic rules apply, but in general, IN returns TRUE if an equal value is found, FALSE if an equal value is excluded, otherwise NULL. NOT IN returns FALSE if an equal value is found, TRUE if an equal value is excluded, otherwise NULL.

• search_value: The expression that's compared to a set of values.

• value_set: One or more values to compare to a search value.

  • (expression[, ...]): A list of expressions.
  • (subquery): A subquery that returns a single column. The values in that column are the set of values. If no rows are produced, the set of values is empty.

  • UNNEST(array_expression): An UNNEST operator that returns a column of values from an array expression. This is equivalent to:

    IN (SELECT element FROM UNNEST(array_expression) AS element) 

This operator supports collation, but these limitations apply:

• [NOT] IN UNNEST doesn't support collation.
• If collation is used with a list of expressions, there must be at least one item in the list.

Semantic rules

When using the IN operator, the following semantics apply in this order:

• Returns FALSE if value_set is empty.
• Returns NULL if search_value is NULL.
• Returns TRUE if value_set contains a value equal to search_value.
• Returns NULL if value_set contains a NULL.
• Returns FALSE.

When using the NOT IN operator, the following semantics apply in this order:

• Returns TRUE if value_set is empty.
• Returns NULL if search_value is NULL.
• Returns FALSE if value_set contains a value equal to search_value.
• Returns NULL if value_set contains a NULL.
• Returns TRUE.

The semantics of:

x IN (y, z, ...) 

are defined as equivalent to:

(x = y) OR (x = z) OR ... 

and the subquery and array forms are defined similarly.

x NOT IN ... 

is equivalent to:

NOT(x IN ...) 

The UNNEST form treats an array scan like UNNEST in the FROM clause:

x [NOT] IN UNNEST(<array expression>) 

This form is often used with array parameters. For example:

x IN UNNEST(@array_parameter) 

See the Arrays topic for more information on how to use this syntax.

IN can be used with multi-part keys by using the struct constructor syntax. For example:

(Key1, Key2) IN ( (12,34), (56,78) ) (Key1, Key2) IN ( SELECT (table.a, table.b) FROM table ) 

See the Struct Type topic for more information.

Return Data Type

BOOL

Examples

You can use these WITH clauses to emulate temporary tables for Words and Items in the following examples:

WITH Words AS (   SELECT 'Intend' as value UNION ALL   SELECT 'Secure' UNION ALL   SELECT 'Clarity' UNION ALL   SELECT 'Peace' UNION ALL   SELECT 'Intend'  ) SELECT * FROM Words;  /*----------+  | value    |  +----------+  | Intend   |  | Secure   |  | Clarity  |  | Peace    |  | Intend   |  +----------*/ 

WITH   Items AS (     SELECT STRUCT('blue' AS color, 'round' AS shape) AS info UNION ALL     SELECT STRUCT('blue', 'square') UNION ALL     SELECT STRUCT('red', 'round')   ) SELECT * FROM Items;  /*----------------------------+  | info                       |  +----------------------------+  | {blue color, round shape}  |  | {blue color, square shape} |  | {red color, round shape}   |  +----------------------------*/ 

Example with IN and an expression:

SELECT * FROM Words WHERE value IN ('Intend', 'Secure');  /*----------+  | value    |  +----------+  | Intend   |  | Secure   |  | Intend   |  +----------*/ 

Example with NOT IN and an expression:

SELECT * FROM Words WHERE value NOT IN ('Intend');  /*----------+  | value    |  +----------+  | Secure   |  | Clarity  |  | Peace    |  +----------*/ 

Example with IN, a scalar subquery, and an expression:

SELECT * FROM Words WHERE value IN ((SELECT 'Intend'), 'Clarity');  /*----------+  | value    |  +----------+  | Intend   |  | Clarity  |  | Intend   |  +----------*/ 

Example with IN and an UNNEST operation:

SELECT * FROM Words WHERE value IN UNNEST(['Secure', 'Clarity']);  /*----------+  | value    |  +----------+  | Secure   |  | Clarity  |  +----------*/ 

Example with IN and a struct:

SELECT   (SELECT AS STRUCT Items.info) as item FROM   Items WHERE (info.shape, info.color) IN (('round', 'blue'));  /*------------------------------------+  | item                               |  +------------------------------------+  | { {blue color, round shape} info } |  +------------------------------------*/ 

IS operators

IS operators return TRUE or FALSE for the condition they are testing. They never return NULL, even for NULL inputs, unlike the IS_INF and IS_NAN functions defined in Mathematical Functions. If NOT is present, the output BOOL value is inverted.

IS DISTINCT FROM operator

expression_1 IS [NOT] DISTINCT FROM expression_2 

Description

IS DISTINCT FROM returns TRUE if the input values are considered to be distinct from each other by the DISTINCT and GROUP BY clauses. Otherwise, returns FALSE.

a IS DISTINCT FROM b being TRUE is equivalent to:

• SELECT COUNT(DISTINCT x) FROM UNNEST([a,b]) x returning 2.
• SELECT * FROM UNNEST([a,b]) x GROUP BY x returning 2 rows.

a IS DISTINCT FROM b is equivalent to NOT (a = b), except for the following cases:

• This operator never returns NULL so NULL values are considered to be distinct from non-NULL values, not other NULL values.
• NaN values are considered to be distinct from non-NaN values, but not other NaN values.

You can use this operation with fields in a complex data type, but not on the complex data types themselves. These complex data types can't be compared directly:

• STRUCT
• ARRAY

Input values:

• expression_1: The first value to compare. This can be a groupable data type, NULL or NaN.
• expression_2: The second value to compare. This can be a groupable data type, NULL or NaN.
• NOT: If present, the output BOOL value is inverted.

Return type

BOOL

Examples

These return TRUE:

SELECT 1 IS DISTINCT FROM 2 

SELECT 1 IS DISTINCT FROM NULL 

SELECT 1 IS NOT DISTINCT FROM 1 

SELECT NULL IS NOT DISTINCT FROM NULL 

These return FALSE:

SELECT NULL IS DISTINCT FROM NULL 

SELECT 1 IS DISTINCT FROM 1 

SELECT 1 IS NOT DISTINCT FROM 2 

SELECT 1 IS NOT DISTINCT FROM NULL 

LIKE operator

expression_1 [NOT] LIKE expression_2 

Description

LIKE returns TRUE if the string in the first operand expression_1 matches a pattern specified by the second operand expression_2, otherwise returns FALSE.

NOT LIKE returns TRUE if the string in the first operand expression_1 doesn't match a pattern specified by the second operand expression_2, otherwise returns FALSE.

Expressions can contain these characters:

• A percent sign (%) matches any number of characters or bytes.
• An underscore (_) matches a single character or byte.
• You can escape \, _, or % using two backslashes. For example, \\%. If you are using raw strings, only a single backslash is required. For example, r'\%'.

This operator supports collation, but caveats apply:

• Each % character in expression_2 represents an arbitrary string specifier. An arbitrary string specifier can represent any sequence of 0 or more characters.

• A character in the expression represents itself and is considered a single character specifier unless:

  • The character is a percent sign (%).

  • The character is an underscore (_) and the collator isn't und:ci.

• These additional rules apply to the underscore (_) character:

  • If the collator isn't und:ci, an error is produced when an underscore isn't escaped in expression_2.

  • If the collator isn't und:ci, the underscore isn't allowed when the operands have collation specified.

  • Some compatibility composites, such as the fi-ligature (fi) and the telephone sign (℡), will produce a match if they are compared to an underscore.

  • A single underscore matches the idea of what a character is, based on an approximation known as a grapheme cluster.

• For a contiguous sequence of single character specifiers, equality depends on the collator and its language tags and tailoring.

  • By default, the und:ci collator doesn't fully normalize a string. Some canonically equivalent strings are considered unequal for both the = and LIKE operators.

  • The LIKE operator with collation has the same behavior as the = operator when there are no wildcards in the strings.

  • Character sequences with secondary or higher-weighted differences are considered unequal. This includes accent differences and some special cases.

    For example there are three ways to produce German sharp ß:

    • \u1E9E
    • \U00DF
    • ss

    \u1E9E and \U00DF are considered equal but differ in tertiary. They are considered equal with und:ci collation but different from ss, which has secondary differences.

  • Character sequences with tertiary or lower-weighted differences are considered equal. This includes case differences and kana subtype differences, which are considered equal.

• There are ignorable characters defined in Unicode. Ignorable characters are ignored in the pattern matching.

Return type

BOOL

Examples

The following examples illustrate how you can check to see if the string in the first operand matches a pattern specified by the second operand.

-- Returns TRUE SELECT 'apple' LIKE 'a%'; 

-- Returns FALSE SELECT '%a' LIKE 'apple'; 

-- Returns FALSE SELECT 'apple' NOT LIKE 'a%'; 

-- Returns TRUE SELECT '%a' NOT LIKE 'apple'; 

-- Produces an error SELECT NULL LIKE 'a%'; 

-- Produces an error SELECT 'apple' LIKE NULL; 

The following example illustrates how to search multiple patterns in an array to find a match with the LIKE operator:

WITH Words AS  (SELECT 'Intend with clarity.' as value UNION ALL   SELECT 'Secure with intention.' UNION ALL   SELECT 'Clarity and security.') SELECT value FROM Words WHERE   EXISTS(     SELECT value FROM UNNEST(['%ity%', '%and%']) AS pattern     WHERE value LIKE pattern   );  /*------------------------+  | value                  |  +------------------------+  | Intend with clarity.   |  | Clarity and security.  |  +------------------------*/ 

The following examples illustrate how collation can be used with the LIKE operator.

-- Returns FALSE 'Foo' LIKE '%foo%' 

-- Returns TRUE COLLATE('Foo', 'und:ci') LIKE COLLATE('%foo%', 'und:ci'); 

-- Returns TRUE COLLATE('Foo', 'und:ci') = COLLATE('foo', 'und:ci'); 

-- Produces an error COLLATE('Foo', 'und:ci') LIKE COLLATE('%foo%', 'binary'); 

-- Produces an error COLLATE('Foo', 'und:ci') LIKE COLLATE('%f_o%', 'und:ci'); 

-- Returns TRUE COLLATE('Foo_', 'und:ci') LIKE COLLATE('%foo\\_%', 'und:ci'); 

There are two capital forms of ß. We can use either SS or ẞ as upper case. While the difference between ß and ẞ is case difference (tertiary difference), the difference between sharp s and ss is secondary and considered not equal using the und:ci collator. For example:

-- Returns FALSE 'MASSE' LIKE 'Maße'; 

-- Returns FALSE COLLATE('MASSE', 'und:ci') LIKE '%Maße%'; 

-- Returns FALSE COLLATE('MASSE', 'und:ci') = COLLATE('Maße', 'und:ci'); 

The kana differences in Japanese are considered as tertiary or quaternary differences, and should be considered as equal in the und:ci collator with secondary strength.

• '\u3042' is 'あ' (hiragana)
• '\u30A2' is 'ア' (katakana)

For example:

-- Returns FALSE '\u3042' LIKE '%\u30A2%'; 

-- Returns TRUE COLLATE('\u3042', 'und:ci') LIKE COLLATE('%\u30A2%', 'und:ci'); 

-- Returns TRUE COLLATE('\u3042', 'und:ci') = COLLATE('\u30A2', 'und:ci'); 

When comparing two strings, the und:ci collator compares the collation units based on the specification of the collation. Even though the number of code points is different, the two strings are considered equal when the collation units are considered the same.

• '\u0041\u030A' is 'Å' (two code points)
• '\u0061\u030A' is 'å' (two code points)
• '\u00C5' is 'Å' (one code point)

In the following examples, the difference between '\u0061\u030A' and '\u00C5' is tertiary.

-- Returns FALSE '\u0061\u030A' LIKE '%\u00C5%'; 

-- Returns TRUE COLLATE('\u0061\u030A', 'und:ci') LIKE '%\u00C5%'; 

-- Returns TRUE COLLATE('\u0061\u030A', 'und:ci') = COLLATE('\u00C5', 'und:ci'); 

In the following example, '\u0083' is a NO BREAK HERE character and is ignored.

-- Returns FALSE '\u0083' LIKE ''; 

-- Returns TRUE COLLATE('\u0083', 'und:ci') LIKE ''; 

Quantified LIKE operator

The quantified LIKE operator supports the following syntax:

search_value [NOT] LIKE quantifier patterns  quantifier:  { ANY | SOME | ALL }  patterns:   {     pattern_expression_list     | pattern_array   }  pattern_expression_list:   (expression[, ...])  pattern_array:   UNNEST(array_expression) 

Description

Checks search_value for matches against several patterns. Each comparison is case-sensitive. Wildcard searches are supported. Semantic rules apply, but in general, LIKE returns TRUE if a matching pattern is found, FALSE if a matching pattern isn't found, or otherwise NULL. NOT LIKE returns FALSE if a matching pattern is found, TRUE if a matching pattern isn't found, or otherwise NULL.

• search_value: The value to search for matching patterns. This value can be a STRING or BYTES type.

• patterns: The patterns to look for in the search value. Each pattern must resolve to the same type as search_value.

  • pattern_expression_list: A list of one or more patterns that match the search_value type.

  • pattern_array: An UNNEST operation that returns a column of values with the same type as search_value from an array expression.

  The regular expressions that are supported by the LIKE operator are also supported by patterns in the quantified LIKE operator.

• quantifier: Condition for pattern matching.

  • ANY: Checks if the set of patterns contains at least one pattern that matches the search value.

  • SOME: Synonym for ANY.

  • ALL: Checks if every pattern in the set of patterns matches the search value.

Collation caveats

Collation is supported, but with the following caveats:

• The collation caveats that apply to the LIKE operator also apply to the quantified LIKE operator.
• If a collation-supported input contains no collation specification or an empty collation specification and another input contains an explicitly defined collation, the explicitly defined collation is used for all of the inputs.
• All inputs with a non-empty, explicitly defined collation specification must have the same type of collation specification, otherwise an error is thrown.

Semantics rules

When using the quantified LIKE operator with ANY or SOME, the following semantics apply in this order:

• Returns FALSE if patterns is empty.
• Returns NULL if search_value is NULL.
• Returns TRUE if search_value matches at least one value in patterns.
• Returns NULL if a pattern in patterns is NULL and other patterns in patterns don't match.
• Returns FALSE.

When using the quantified LIKE operator with ALL, the following semantics apply in this order:

• For pattern_array, returns FALSE if patterns is empty.
• Returns NULL if search_value is NULL.
• Returns TRUE if search_value matches all values in patterns.
• Returns NULL if a pattern in patterns is NULL and other patterns in patterns don't match.
• Returns FALSE.

When using the quantified NOT LIKE operator with ANY or SOME, the following semantics apply in this order:

• For pattern_array, returns TRUE if patterns is empty.
• Returns NULL if search_value is NULL.
• Returns TRUE if search_value doesn't match at least one value in patterns.
• Returns NULL if a pattern in patterns is NULL and other patterns in patterns don't match.
• Returns FALSE.

When using the quantified NOT LIKE operator with ALL, the following semantics apply in this order:

• For pattern_array, returns TRUE if patterns is empty.
• Returns NULL if search_value is NULL.
• Returns TRUE if search_value matches none of the values in patterns.
• Returns NULL if a pattern in patterns is NULL and other patterns in patterns don't match.
• Returns FALSE.

Return Data Type

BOOL

Examples

The following example checks to see if the Intend% or %intention% pattern exists in a value and produces that value if either pattern is found:

WITH Words AS  (SELECT 'Intend with clarity.' as value UNION ALL   SELECT 'Secure with intention.' UNION ALL   SELECT 'Clarity and security.') SELECT * FROM Words WHERE value LIKE ANY ('Intend%', '%intention%');  /*------------------------+  | value                  |  +------------------------+  | Intend with clarity.   |  | Secure with intention. |  +------------------------*/ 

The following example checks to see if the %ity% pattern exists in a value and produces that value if the pattern is found.

Example with LIKE ALL:

WITH Words AS  (SELECT 'Intend with clarity.' as value UNION ALL   SELECT 'Secure with intention.' UNION ALL   SELECT 'Clarity and security.') SELECT * FROM Words WHERE value LIKE ALL ('%ity%');  /*-----------------------+  | value                 |  +-----------------------+  | Intend with clarity.  |  | Clarity and security. |  +-----------------------*/ 

The following example checks to see if the %ity% pattern exists in a value produces that value if the pattern isn't found:

WITH Words AS  (SELECT 'Intend with clarity.' as value UNION ALL   SELECT 'Secure with intention.' UNION ALL   SELECT 'Clarity and security.') SELECT * FROM Words WHERE value NOT LIKE ('%ity%');  /*------------------------+  | value                  |  +------------------------+  | Secure with intention. |  +------------------------*/ 

You can pass in an array for patterns. For example:

WITH Words AS  (SELECT 'Intend with clarity.' as value UNION ALL   SELECT 'Secure with intention.' UNION ALL   SELECT 'Clarity and security.') SELECT * FROM Words WHERE value LIKE ANY UNNEST(['%ion%', '%and%']);  /*------------------------+  | value                  |  +------------------------+  | Secure with intention. |  | Clarity and security.  |  +------------------------*/ 

The following queries illustrate some of the semantic rules for the quantified LIKE operator:

SELECT   NULL LIKE ANY ('a', 'b'), -- NULL   'a' LIKE ANY ('a', 'c'), -- TRUE   'a' LIKE ANY ('b', 'c'), -- FALSE   'a' LIKE ANY ('a', NULL), -- TRUE   'a' LIKE ANY ('b', NULL), -- NULL   NULL NOT LIKE ANY ('a', 'b'), -- NULL   'a' NOT LIKE ANY ('a', 'b'), -- TRUE   'a' NOT LIKE ANY ('a', '%a%'), -- FALSE   'a' NOT LIKE ANY ('a', NULL), -- NULL   'a' NOT LIKE ANY ('b', NULL); -- TRUE 

SELECT   NULL LIKE SOME ('a', 'b'), -- NULL   'a' LIKE SOME ('a', 'c'), -- TRUE   'a' LIKE SOME ('b', 'c'), -- FALSE   'a' LIKE SOME ('a', NULL), -- TRUE   'a' LIKE SOME ('b', NULL), -- NULL   NULL NOT LIKE SOME ('a', 'b'), -- NULL   'a' NOT LIKE SOME ('a', 'b'), -- TRUE   'a' NOT LIKE SOME ('a', '%a%'), -- FALSE   'a' NOT LIKE SOME ('a', NULL), -- NULL   'a' NOT LIKE SOME ('b', NULL); -- TRUE 

SELECT   NULL LIKE ALL ('a', 'b'), -- NULL   'a' LIKE ALL ('a', '%a%'), -- TRUE   'a' LIKE ALL ('a', 'c'), -- FALSE   'a' LIKE ALL ('a', NULL), -- NULL   'a' LIKE ALL ('b', NULL), -- FALSE   NULL NOT LIKE ALL ('a', 'b'), -- NULL   'a' NOT LIKE ALL ('b', 'c'), -- TRUE   'a' NOT LIKE ALL ('a', 'c'), -- FALSE   'a' NOT LIKE ALL ('a', NULL), -- FALSE   'a' NOT LIKE ALL ('b', NULL); -- NULL 

The following queries illustrate some of the semantic rules for the quantified LIKE operator and collation:

SELECT   COLLATE('a', 'und:ci') LIKE ALL ('a', 'A'), -- TRUE   'a' LIKE ALL (COLLATE('a', 'und:ci'), 'A'), -- TRUE   'a' LIKE ALL ('%A%', COLLATE('a', 'und:ci')); -- TRUE 

-- ERROR: BYTES and STRING values can't be used together. SELECT b'a' LIKE ALL (COLLATE('a', 'und:ci'), 'A'); 

Concatenation operator

The concatenation operator combines multiple values into one.

WITH expression

WITH(variable_assignment[, ...], result_expression)  variable_assignment:   variable_name AS expression 

Description

Creates one or more variables. Each variable can be used in subsequent expressions within the WITH expression. Returns the value of result_expression.

• variable_assignment: Introduces a variable. The variable name must be unique within a given WITH expression. Each expression can reference the variables that come before it. For example, if you create variable a, then follow it with variable b, then you can reference a inside of the expression for b.

  • variable_name: The name of the variable.

  • expression: The value to assign to the variable.

• result_expression: An expression that can use all of the variables defined before it. The value of result_expression is returned by the WITH expression.

Return Type

• The type of the result_expression.

Requirements and Caveats

• A variable can only be assigned once within a WITH expression.
• Variables created during WITH may not be used in analytic or aggregate function arguments. For example, WITH(a AS ..., SUM(a)) produces an error.
• Each variable's expression is evaluated only once.

Examples

The following example first concatenates variable a with b, then variable b with c:

SELECT WITH(a AS '123',               -- a is '123'             b AS CONCAT(a, '456'),    -- b is '123456'             c AS '789',               -- c is '789'             CONCAT(b, c)) AS result;  -- b + c is '123456789'  /*-------------+  | result      |  +-------------+  | '123456789' |  +-------------*/ 

In the following example, the volatile expression RAND() is evaluated once. The value of the result expression is always 0.0:

SELECT WITH(a AS RAND(), a - a);  /*---------+  | result  |  +---------+  | 0.0     |  +---------*/ 

Aggregate or analytic function results can be stored in variables.

SELECT WITH(s AS SUM(input), c AS COUNT(input), s/c) FROM UNNEST([1.0, 2.0, 3.0]) AS input;  /*---------+  | result  |  +---------+  | 2.0     |  +---------*/ 

Variables can't be used in aggregate or analytic function call arguments.

SELECT WITH(diff AS a - b, AVG(diff)) FROM UNNEST([               STRUCT(1 AS a, 2 AS b),               STRUCT(3 AS a, 4 AS b),               STRUCT(5 AS a, 6 AS b)             ]);  -- ERROR: WITH variables like 'diff' can't be used in aggregate or analytic -- function arguments. 

A WITH expression is different from a WITH clause. The following example shows a query that uses both:

WITH my_table AS (   SELECT 1 AS x, 2 AS y   UNION ALL   SELECT 3 AS x, 4 AS y   UNION ALL   SELECT 5 AS x, 6 AS y ) SELECT WITH(a AS SUM(x), b AS COUNT(x), a/b) AS avg_x, AVG(y) AS avg_y FROM my_table WHERE x > 1;  /*-------+-------+  | avg_x | avg_y |  +-------+-------+  | 4     | 5     |  +-------+-------*/