Operators
January 30, 2026 · View on GitHub
GoogleSQL 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
NULLwhen one of the operands isNULL. - All operators will throw an error if the computation result overflows.
- For all floating point operations,
+/-infandNaNmay only be returned if one of the operands is+/-inforNaN. 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.
<tr>
<td> </td>
<td>Array elements field access operator</td>
<td><code>ARRAY</code></td>
<td>Field access operator for elements in an array</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td>Array subscript operator</td>
<td><code>ARRAY</code></td>
<td>Array position. Must be used with <code>OFFSET</code> or <code>ORDINAL</code>—see
<a href="https://github.com/google/googlesql/blob/master/docs/array_functions.md">Array Functions</a>
.
<tr>
<td> </td>
<td>JSON subscript operator</td>
<td><code>JSON</code></td>
<td>Field name or array position in JSON.</td>
<td>Binary</td>
</tr>
<tr>
<td>2</td>
<td><code>+</code></td>
<td>All numeric types</td>
<td>Unary plus</td>
<td>Unary</td>
</tr>
<tr>
<td> </td>
<td><code>-</code></td>
<td>All numeric types</td>
<td>Unary minus</td>
<td>Unary</td>
</tr>
<tr>
<td> </td>
<td><code>~</code></td>
<td>Integer or <code>BYTES</code></td>
<td>Bitwise not</td>
<td>Unary</td>
</tr>
<tr>
<td>3</td>
<td><code>*</code></td>
<td>All numeric types</td>
<td>Multiplication</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td><code>/</code></td>
<td>All numeric types</td>
<td>Division</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td><code>||</code></td>
<td><code>STRING</code>, <code>BYTES</code>, or <code>ARRAY<T></code></td>
<td>Concatenation operator</td>
<td>Binary</td>
</tr>
<tr>
<td>4</td>
<td><code>+</code></td>
<td>
All numeric types, <code>DATE</code> with
<code>INT64</code>
, <code>INTERVAL</code>
</td>
<td>Addition</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td><code>-</code></td>
<td>
All numeric types, <code>DATE</code> with
<code>INT64</code>
, <code>INTERVAL</code>
</td>
<td>Subtraction</td>
<td>Binary</td>
</tr>
<tr>
<td>5</td>
<td><code><<</code></td>
<td>Integer or <code>BYTES</code></td>
<td>Bitwise left-shift</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td><code>>></code></td>
<td>Integer or <code>BYTES</code></td>
<td>Bitwise right-shift</td>
<td>Binary</td>
</tr>
<tr>
<td>6</td>
<td><code>&</code></td>
<td>Integer or <code>BYTES</code></td>
<td>Bitwise and</td>
<td>Binary</td>
</tr>
<tr>
<td>7</td>
<td><code>^</code></td>
<td>Integer or <code>BYTES</code></td>
<td>Bitwise xor</td>
<td>Binary</td>
</tr>
<tr>
<td>8</td>
<td><code>|</code></td>
<td>Integer or <code>BYTES</code></td>
<td>Bitwise or</td>
<td>Binary</td>
</tr>
<tr>
<td>9 (Comparison Operators)</td>
<td><code>=</code></td>
<td>Any comparable type. See
<a href="https://github.com/google/googlesql/blob/master/docs/data-types.md">Data Types</a>
for a complete list.</td>
<td>Equal</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td><code><</code></td>
<td>Any comparable type. See
<a href="https://github.com/google/googlesql/blob/master/docs/data-types.md">Data Types</a>
for a complete list.</td>
<td>Less than</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td><code>></code></td>
<td>Any comparable type. See
<a href="https://github.com/google/googlesql/blob/master/docs/data-types.md">Data Types</a>
for a complete list.</td>
<td>Greater than</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td><code><=</code></td>
<td>Any comparable type. See
<a href="https://github.com/google/googlesql/blob/master/docs/data-types.md">Data Types</a>
for a complete list.</td>
<td>Less than or equal to</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td><code>>=</code></td>
<td>Any comparable type. See
<a href="https://github.com/google/googlesql/blob/master/docs/data-types.md">Data Types</a>
for a complete list.</td>
<td>Greater than or equal to</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td><code>!=</code>, <code><></code></td>
<td>Any comparable type. See
<a href="https://github.com/google/googlesql/blob/master/docs/data-types.md">Data Types</a>
for a complete list.</td>
<td>Not equal</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td><code>[NOT] LIKE</code></td>
<td><code>STRING</code> and <code>BYTES</code></td>
<td>Value does [not] match the pattern specified</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td><code>[NOT] BETWEEN</code></td>
<td>Any comparable types. See
<a href="https://github.com/google/googlesql/blob/master/docs/data-types.md">Data Types</a>
for a complete list.</td>
<td>Value is [not] within the range specified</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td><code>[NOT] IN</code></td>
<td>Any comparable types. See
<a href="https://github.com/google/googlesql/blob/master/docs/data-types.md">Data Types</a>
for a complete list.</td>
<td>Value is [not] in the set of values specified</td>
<td>Binary</td>
</tr>
<tr>
<td> </td>
<td><code>IS [NOT] NULL</code></td>
<td>All</td>
<td>Value is [not] <code>NULL</code></td>
<td>Unary</td>
</tr>
<tr>
<td> </td>
<td><code>IS [NOT] TRUE</code></td>
<td><code>BOOL</code></td>
<td>Value is [not] <code>TRUE</code>.</td>
<td>Unary</td>
</tr>
<tr>
<td> </td>
<td><code>IS [NOT] FALSE</code></td>
<td><code>BOOL</code></td>
<td>Value is [not] <code>FALSE</code>.</td>
<td>Unary</td>
</tr>
<tr>
<td>10</td>
<td><code>NOT</code></td>
<td><code>BOOL</code></td>
<td>Logical <code>NOT</code></td>
<td>Unary</td>
</tr>
<tr>
<td>11</td>
<td><code>AND</code></td>
<td><code>BOOL</code></td>
<td>Logical <code>AND</code></td>
<td>Binary</td>
</tr>
<tr>
<td>12</td>
<td><code>OR</code></td>
<td><code>BOOL</code></td>
<td>Logical <code>OR</code></td>
<td>Binary</td>
</tr>
| Order of Precedence | Operator | Input Data Types | Name | Operator Arity |
|---|---|---|---|---|
| 1 | Field access operator |
|
Field access operator | Binary |
| Binary | ||||
| Quantified LIKE | STRING and BYTES |
Checks a search value for matches against several patterns. | Binary |
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
| Name | Summary |
|---|---|
| Field access operator | Gets the value of a field. |
| Array subscript operator | Gets a value from an array at a specific position. |
| Struct subscript operator | Gets the value of a field at a selected position in a struct. |
| JSON subscript operator | Gets a value of an array element or field in a JSON expression. |
| Protocol buffer map subscript operator | Gets the value in a protocol buffer map for a given key. |
| Array elements field access operator | Traverses through the levels of a nested data type inside an array. |
| Arithmetic operators | Performs arithmetic operations. |
| Date arithmetics operators | Performs arithmetic operations on dates. |
| Datetime subtraction | Computes the difference between two datetimes as an interval. |
| Interval arithmetic operators | Adds an interval to a datetime or subtracts an interval from a datetime. |
| Bitwise operators | Performs bit manipulation. |
| Logical operators |
Tests for the truth of some condition and produces TRUE,
FALSE, or NULL.
|
| Graph concatenation operator | Combines multiple graph paths into one and preserves the original order of the nodes and edges. |
| Graph logical operators |
Tests for the truth of a condition in a graph and produces either
TRUE or FALSE.
|
| Graph predicates |
Tests for the truth of a condition for a graph element and produces
TRUE, FALSE, or NULL.
|
IS DESTINATION predicate
|
In a graph, checks to see if a node is or isn't the destination of an edge. |
IS LABELED predicate
|
In a graph, checks to see if a node or edge label satisfies a label expression. |
IS SOURCE predicate
|
In a graph, checks to see if a node is or isn't the source of an edge. |
PROPERTY_EXISTS predicate
|
In a graph, checks to see if a property exists for an element. |
SAME predicate
|
In a graph, checks if all graph elements in a list bind to the same node or edge. |
| Comparison operators |
Compares operands and produces the results of the comparison as a
BOOL value.
|
EXISTS operator
|
Checks if a subquery produces one or more rows. |
IN operator
|
Checks for an equal value in a set of values. |
IS operators
|
Checks for the truth of a condition and produces either TRUE or
FALSE.
|
IS DISTINCT FROM operator
|
Checks if values are considered to be distinct from each other. |
LIKE operator
|
Checks if values are like or not like one another. |
Quantified LIKE operator
|
Checks a search value for matches against several patterns. |
NEW operator
|
Creates a protocol buffer. |
| Concatenation operator | Combines multiple values into one. |
WITH expression
|
Creates variables for re-use and produces a result expression. |
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:
STRUCTPROTOJSONGRAPH_ELEMENT
Note: If the field to access is within a STRUCT, you can use the
struct subscript operator to access the field by
its position within the STRUCT instead of by its name. Accessing by
a field by position is useful when fields are un-named or have ambiguous names.
Return type
- For
STRUCT: SQL data type offieldname. If a field isn't found in the struct, an error is thrown. - For
PROTO: SQL data type offieldname. If a field isn't found in the protocol buffer, an error is thrown. - For
JSON:JSON. If a field isn't found in a JSON value, a SQLNULLis returned. - For
GRAPH_ELEMENT: SQL data type offieldname. If a field (property) isn't found in the graph element, an error 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
Note: Syntax characters enclosed in double quotes ("") are literal and
required.
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 produceNULLinstead of an error, useSAFE_OFFSET(index). This position keyword produces the same result asindexby itself.SAFE_OFFSET(index): The index starts at zero. ReturnsNULLif the index is out of range.ORDINAL(index): The index starts at one. Produces an error if the index is out of range. To produceNULLinstead of an error, useSAFE_ORDINAL(index).SAFE_ORDINAL(index): The index starts at one. ReturnsNULLif 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 produceNULLinstead of an error, use theSAFE_OFFSET(index)orSAFE_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
Note: Syntax characters enclosed in double quotes ("") are literal and
required.
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 asindexby 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.
Note: The struct subscript operator doesn't support SAFE positional keywords
at this time.
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
Note: Syntax characters enclosed in double quotes ("") are literal and
required.
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: TheJSONexpression that contains an array element or field to return.[array_element_id]: AnINT64expression 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 SQLNULLis returned.[field_name]: ASTRINGexpression 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 SQLNULLis returned.
Return type
JSON
Example
In the following example:
json_valueis a JSON expression..classis a JSON field access..studentsis 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" |
+-----------------*/
Protocol buffer map subscript operator
proto_map_field_expression[proto_subscript_specifier]
proto_subscript_specifier:
key_name | key_keyword(key_name)
key_keyword:
{ KEY | SAFE_KEY }
Description
Returns the value in a protocol buffer map for a given key.
Input values:
proto_map_field_expression: A protocol buffer map field.key_keyword(key_name): Determines whether to produceNULLor an error if the key isn't present in the protocol buffer map field.KEY(key_name): Returns an error if the key isn't present in the protocol buffer map field.SAFE_KEY(key_name): ReturnsNULLif the key isn't present in the protocol buffer map field.key_name: Whenkey_nameis provided without a wrapping keyword, it's the same asKEY(key_name).
key_name: The key in the protocol buffer map field. This operator returnsNULLif the key isNULL.
Return type
In the input protocol buffer map field, V as represented in map<K,V>.
Examples
To illustrate the use of this function, we use the protocol buffer message
Item.
message Item {
optional map<string, int64> purchased = 1;
};
In the following example, the subscript operator returns the value when the key is present.
SELECT
m.purchased[KEY('A')] AS map_value
FROM
(SELECT AS VALUE CAST("purchased { key: 'A' value: 2 }" AS Item)) AS m;
/*-----------+
| map_value |
+-----------+
| 2 |
+-----------*/
When the key doesn't exist in the map field and you use KEY, an error is
produced. For example:
-- ERROR: Key not found in map: 2
SELECT
m.purchased[KEY('B')] AS value
FROM
(SELECT AS VALUE CAST("purchased { key: 'A' value: 2 }" AS Item)) AS m;
When the key doesn't exist in the map field and you use SAFE_KEY,
the subscript operator returns NULL. For example:
SELECT
CAST(m.purchased[SAFE_KEY('B')] AS safe_key_missing
FROM
(SELECT AS VALUE CAST("purchased { key: 'A' value: 2 }" AS Item)) AS m;
/*------------------+
| safe_key_missing |
+------------------+
| NULL |
+------------------*/
The subscript operator returns NULL when the map field or key is NULL.
For example:
SELECT
CAST(NULL AS Item).purchased[KEY('A')] AS null_map,
m.purchased[KEY(NULL)] AS null_key
FROM
(SELECT AS VALUE CAST("purchased { key: 'A' value: 2 }" AS Item)) AS m;
/*-----------------------+
| null_map | null_key |
+-----------------------+
| NULL | NULL |
+-----------------------*/
When a key is used without KEY() or SAFE_KEY(), it has the same behavior
as if KEY() had been used. For example:
SELECT
m.purchased['A'] AS map_value
FROM
(SELECT AS VALUE CAST("purchased { key: 'A' value: 2 }" AS Item)) AS m;
/*-----------+
| map_value |
+-----------+
| 2 |
+-----------*/
Array elements field access operator
Note: Syntax characters enclosed in double quotes ("") are literal and
required.
array_expression.field_or_element[. ...]
field_or_element:
{ fieldname | array_element }
array_element:
array_fieldname "[" array_subscript_specifier "]"
Description
The array elements field access operation lets you traverse through the levels of a nested data type inside an array.
Input values:
-
array_expression: An expression that evaluates to an array value. -
field_or_element[. ...]: The field to access. This can also be a position in an array-typed field. -
fieldname: The name of the field to access.For example, this query returns all values for the
itemsfield inside of themy_arrayarray expression:WITH MyTable AS ( SELECT [STRUCT(['foo', 'bar'] AS items)] AS my_array ) SELECT FLATTEN(my_array.items) FROM MyTableThese data types have fields:
STRUCTPROTOJSON
-
array_element: If the field to access is an array field (array_field), you can additionally access a specific position in the field with the array subscript operator ([array_subscript_specifier]). This operation returns only elements at a selected position, rather than all elements, in the array field.For example, this query only returns values at position 0 in the
itemsarray field:WITH MyTable AS ( SELECT [STRUCT(['foo', 'bar'] AS items)] AS my_array ) SELECT FLATTEN(my_array.items[OFFSET(0)]) FROM MyTable
Details:
The array elements field access operation isn't a typical expression that returns a typed value; it represents a concept outside the type system and can only be interpreted by the following operations:
-
FLATTENoperation: Returns an array. For example:FLATTEN(my_array.sales.prices) -
UNNESToperation: Returns a table.array_expressionmust be a path expression. Implicitly implements theFLATTENoperator. For example, these do the same thing:UNNEST(my_array.sales.prices)UNNEST(FLATTEN(my_array.sales.prices)) -
FROMclause: Returns a table.array_expressionmust be a path expression. Implicitly implements theUNNESToperator and theFLATTENoperator. For example, these unnesting operations produce the same values forresults:SELECT results FROM SalesTable, SalesTable.my_array.sales.prices AS results;SELECT results FROM SalesTable, UNNEST(my_array.sales.prices) AS results;SELECT results FROM SalesTable, UNNEST(FLATTEN(my_array.sales.prices)) AS results;
If NULL array elements are encountered, they are added to the resulting array.
Common shapes of this operation
This operation can take several shapes. The right-most value in the operation determines what type of array is returned. Here are some example shapes and a description of what they return:
The following shapes extract the final non-array field from each element of an array expression and return an array of those non-array field values.
array_expression.non_array_field_1array_expression.non_array_field_1.array_field.non_array_field_2
The following shapes extract the final array field from each element of the
array expression and concatenate the array fields together.
An empty array or a NULL array contributes no elements to the resulting array.
array_expression.non_array_field_1.array_field_1array_expression.non_array_field_1.array_field_1.non_array_field_2.array_field_2array_expression.non_array_field_1.non_array_field_2.array_field_1
The following shapes extract the final array field from each element of the
array expression at a specific position. Then they return an array of those
extracted elements. An empty array or a NULL array contributes no elements
to the resulting array.
array_expression.non_array_field_1.array_field_1[OFFSET(1)]array_expression.non_array_field_1.array_field_1[SAFE_OFFSET(1)]array_expression.non_array_field_1.non_array_field_2.array_field_1[ORDINAL(2)]array_expression.non_array_field_1.non_array_field_2.array_field_1[SAFE_ORDINAL(2)]
Return Value
FLATTENof an array element access operation returns an array.UNNESTof an array element access operation, whether explicit or implicit, returns a table.
Examples
The next examples in this section reference a table called SalesTable, that
contains a nested struct in an array called my_array:
WITH
SalesTable AS (
SELECT
[
STRUCT(
[
STRUCT([25.0, 75.0] AS prices),
STRUCT([30.0] AS prices)
] AS sales
)
] AS my_array
)
SELECT * FROM SalesTable;
/*----------------------------------------------+
| my_array |
+----------------------------------------------+
| [{[{[25, 75] prices}, {[30] prices}] sales}] |
+----------------------------------------------*/
This is what the array elements field access operator looks like in the
FLATTEN operator:
SELECT FLATTEN(my_array.sales.prices) AS all_prices FROM SalesTable;
/*--------------+
| all_prices |
+--------------+
| [25, 75, 30] |
+--------------*/
This is how you use the array subscript operator to only return values at a
specific index in the prices array:
SELECT FLATTEN(my_array.sales.prices[OFFSET(0)]) AS first_prices FROM SalesTable;
/*--------------+
| first_prices |
+--------------+
| [25, 30] |
+--------------*/
This is an example of an explicit UNNEST operation that includes the
array elements field access operator:
SELECT all_prices FROM SalesTable, UNNEST(my_array.sales.prices) AS all_prices
/*------------+
| all_prices |
+------------+
| 25 |
| 75 |
| 30 |
+------------*/
This is an example of an implicit UNNEST operation that includes the
array elements field access operator:
SELECT all_prices FROM SalesTable, SalesTable.my_array.sales.prices AS all_prices
/*------------+
| all_prices |
+------------+
| 25 |
| 75 |
| 30 |
+------------*/
This query produces an error because one of the prices arrays doesn't have
an element at index 1 and OFFSET is used:
SELECT FLATTEN(my_array.sales.prices[OFFSET(1)]) AS second_prices FROM SalesTable;
-- Error
This query is like the previous query, but SAFE_OFFSET is used. This
produces a NULL value instead of an error.
SELECT FLATTEN(my_array.sales.prices[SAFE_OFFSET(1)]) AS second_prices FROM SalesTable;
/*---------------+
| second_prices |
+---------------+
| [75, NULL] |
+---------------*/
In this next example, an empty array and a NULL field value have been added to
the query. These contribute no elements to the result.
WITH
SalesTable AS (
SELECT
[
STRUCT(
[
STRUCT([25.0, 75.0] AS prices),
STRUCT([30.0] AS prices),
STRUCT(ARRAY<DOUBLE>[] AS prices),
STRUCT(NULL AS prices)
] AS sales
)
] AS my_array
)
SELECT FLATTEN(my_array.sales.prices) AS first_prices FROM SalesTable;
/*--------------+
| first_prices |
+--------------+
| [25, 75, 30] |
+--------------*/
The next examples in this section reference a protocol buffer called
Album that looks like this:
message Album {
optional string album_name = 1;
repeated string song = 2;
oneof group_name {
string solo = 3;
string duet = 4;
string band = 5;
}
}
Nested data is common in protocol buffers that have data within repeated
messages. The following example extracts a flattened array of songs from a
table called AlbumList that contains a column called Album of type PROTO.
WITH
AlbumList AS (
SELECT
[
NEW Album(
'One Way' AS album_name,
['North', 'South'] AS song,
'Crossroads' AS band),
NEW Album(
'After Hours' AS album_name,
['Snow', 'Ice', 'Water'] AS song,
'Sunbirds' AS band)]
AS albums_array
)
SELECT FLATTEN(albums_array.song) AS songs FROM AlbumList
/*------------------------------+
| songs |
+------------------------------+
| [North,South,Snow,Ice,Water] |
+------------------------------*/
The following example extracts a flattened array of album names, one album name
per row. The data comes from a table called AlbumList that contains a
proto-typed column called Album.
WITH
AlbumList AS (
SELECT
[
(
SELECT
NEW Album(
'One Way' AS album_name,
['North', 'South'] AS song,
'Crossroads' AS band) AS album_col
),
(
SELECT
NEW Album(
'After Hours' AS album_name,
['Snow', 'Ice', 'Water'] AS song,
'Sunbirds' AS band) AS album_col
)]
AS albums_array
)
SELECT names FROM AlbumList, UNNEST(albums_array.album_name) AS names
/*----------------------+
| names |
+----------------------+
| One Way |
| After Hours |
+----------------------*/
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:
| Name | Syntax |
|---|---|
| Addition | X + Y |
| Subtraction | X - Y |
| Multiplication | X * Y |
| Division | X / Y |
| Unary Plus | + X |
| Unary Minus | - X |
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 and Multiplication:
| INPUT | INT32 | INT64 | UINT32 | UINT64 | NUMERIC | BIGNUMERIC | FLOAT | DOUBLE |
|---|---|---|---|---|---|---|---|---|
INT32 | INT64 | INT64 | INT64 | ERROR | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
INT64 | INT64 | INT64 | INT64 | ERROR | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
UINT32 | INT64 | INT64 | UINT64 | UINT64 | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
UINT64 | ERROR | ERROR | UINT64 | UINT64 | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
NUMERIC | NUMERIC | NUMERIC | NUMERIC | NUMERIC | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
FLOAT | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE |
DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE |
Result types for Subtraction:
| INPUT | INT32 | INT64 | UINT32 | UINT64 | NUMERIC | BIGNUMERIC | FLOAT | DOUBLE |
|---|---|---|---|---|---|---|---|---|
INT32 | INT64 | INT64 | INT64 | ERROR | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
INT64 | INT64 | INT64 | INT64 | ERROR | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
UINT32 | INT64 | INT64 | INT64 | INT64 | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
UINT64 | ERROR | ERROR | INT64 | INT64 | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
NUMERIC | NUMERIC | NUMERIC | NUMERIC | NUMERIC | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
FLOAT | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE |
DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE |
Result types for Division:
| INPUT | INT32 | INT64 | UINT32 | UINT64 | NUMERIC | BIGNUMERIC | FLOAT | DOUBLE |
|---|---|---|---|---|---|---|---|---|
INT32 | DOUBLE | DOUBLE | DOUBLE | DOUBLE | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
INT64 | DOUBLE | DOUBLE | DOUBLE | DOUBLE | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
UINT32 | DOUBLE | DOUBLE | DOUBLE | DOUBLE | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
UINT64 | DOUBLE | DOUBLE | DOUBLE | DOUBLE | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
NUMERIC | NUMERIC | NUMERIC | NUMERIC | NUMERIC | NUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | BIGNUMERIC | DOUBLE | DOUBLE |
FLOAT | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE |
DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE | DOUBLE |
Result types for Unary Plus:
| INPUT | INT32 | INT64 | UINT32 | UINT64 | NUMERIC | BIGNUMERIC | FLOAT | DOUBLE |
|---|---|---|---|---|---|---|---|---|
| OUTPUT | INT32 | INT64 | UINT32 | UINT64 | NUMERIC | BIGNUMERIC | FLOAT | DOUBLE |
Result types for Unary Minus:
| INPUT | INT32 | INT64 | UINT32 | UINT64 | NUMERIC | BIGNUMERIC | FLOAT | DOUBLE |
|---|---|---|---|---|---|---|---|---|
| OUTPUT | INT32 | INT64 | ERROR | ERROR | NUMERIC | BIGNUMERIC | FLOAT | DOUBLE |
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+00" - 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.
| Name | Syntax | Input Data Type | Description |
|---|---|---|---|
| Bitwise not | ~ X |
Integer or BYTES |
Performs logical negation on each bit, forming the ones' complement of the given binary value. |
| Bitwise or | X | Y |
X: Integer or BYTESY: Same type as X
|
Takes two bit patterns of equal length and performs the logical inclusive
OR operation on each pair of the corresponding bits.
This operator throws an error if |
| Bitwise xor | X ^ Y |
X: Integer or BYTESY: Same type as X
|
Takes two bit patterns of equal length and performs the
logical exclusive OR operation on each pair of the corresponding
bits.
This operator throws an error if |
| Bitwise and | X & Y |
X: Integer or BYTESY: Same type as X
|
Takes two bit patterns of equal length and performs the
logical AND operation on each pair of the corresponding bits.
This operator throws an error if |
| Left shift | X << Y |
X: Integer or BYTESY: INT64
|
Shifts the first operand X to the left.
This operator returns
0 or a byte sequence of b'\x00'
if the second operand Y is greater than or equal to
the bit length of the first operand This operator throws an error if |
| Right shift | X >> Y |
X: Integer or BYTESY: INT64 |
Shifts the first operand X to the right. This operator doesn't
perform sign bit extension with a signed type (i.e., it fills vacant bits on the left
with 0). This operator returns
0 or a byte sequence of
b'\x00'
if the second operand Y is greater than or equal to
the bit length of the first operand This operator throws an error if |
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:
x | y | x AND y | x OR y |
|---|---|---|---|
TRUE | TRUE | TRUE | TRUE |
TRUE | FALSE | FALSE | TRUE |
TRUE | NULL | NULL | TRUE |
FALSE | TRUE | FALSE | TRUE |
FALSE | FALSE | FALSE | FALSE |
FALSE | NULL | FALSE | NULL |
NULL | TRUE | NULL | TRUE |
NULL | FALSE | FALSE | NULL |
NULL | NULL | NULL | NULL |
x | NOT x |
|---|---|
TRUE | FALSE |
FALSE | TRUE |
NULL | 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 |
+-------*/
Graph concatenation operator
graph_path || graph_path [ || ... ]
Description
Combines multiple graph paths into one and preserves the original order of the nodes and edges.
Arguments:
graph_path: AGRAPH_PATHvalue that represents a graph path to concatenate.
Details
This operator produces an error if the last node in the first path isn't the same as the first node in the second path.
-- This successfully produces the concatenated path called `full_path`.
MATCH
p=(src:Account)-[t1:Transfers]->(mid:Account),
q=(mid)-[t2:Transfers]->(dst:Account)
LET full_path = p || q
-- This produces an error because the first node of the path to be concatenated
-- (mid2) isn't equal to the last node of the previous path (mid1).
MATCH
p=(src:Account)-[t1:Transfers]->(mid1:Account),
q=(mid2:Account)-[t2:Transfers]->(dst:Account)
LET full_path = p || q
The first node in each subsequent path is removed from the concatenated path.
-- The concatenated path called `full_path` contains these elements:
-- src, t1, mid, t2, dst.
MATCH
p=(src:Account)-[t1:Transfers]->(mid:Account),
q=(mid)-[t2:Transfers]->(dst:Account)
LET full_path = p || q
If any graph_path is NULL, produces NULL.
Example
In the following query, a path called p and q are concatenated. Notice that
mid is used at the end of the first path and at the beginning of the
second path. Also notice that the duplicate mid is removed from the
concatenated path called full_path:
GRAPH FinGraph
MATCH
p=(src:Account)-[t1:Transfers]->(mid:Account),
q = (mid)-[t2:Transfers]->(dst:Account)
LET full_path = p || q
RETURN
JSON_QUERY(TO_JSON(full_path)[0], '$.labels') AS element_a,
JSON_QUERY(TO_JSON(full_path)[1], '$.labels') AS element_b,
JSON_QUERY(TO_JSON(full_path)[2], '$.labels') AS element_c,
JSON_QUERY(TO_JSON(full_path)[3], '$.labels') AS element_d,
JSON_QUERY(TO_JSON(full_path)[4], '$.labels') AS element_e,
JSON_QUERY(TO_JSON(full_path)[5], '$.labels') AS element_f
/*-------------------------------------------------------------------------------------+
| element_a | element_b | element_c | element_d | element_e | element_f |
+-------------------------------------------------------------------------------------+
| ["Account"] | ["Transfers"] | ["Account"] | ["Transfers"] | ["Account"] | |
| ... | ... | ... | ... | ... | ... |
+-------------------------------------------------------------------------------------/*
The following query produces an error because the last node for p must
be the first node for q:
-- Error: `mid1` and `mid2` aren't equal.
GRAPH FinGraph
MATCH
p=(src:Account)-[t1:Transfers]->(mid1:Account),
q=(mid2:Account)-[t2:Transfers]->(dst:Account)
LET full_path = p || q
RETURN TO_JSON(full_path) AS results
The following query produces an error because the path called p is NULL:
-- Error: a graph path is NULL.
GRAPH FinGraph
MATCH
p=NULL,
q=(mid:Account)-[t2:Transfers]->(dst:Account)
LET full_path = p || q
RETURN TO_JSON(full_path) AS results
Graph logical operators
GoogleSQL supports the following logical operators in element pattern label expressions:
| Name | Syntax | Description |
|---|---|---|
NOT |
!X |
Returns TRUE if X isn't included, otherwise,
returns FALSE.
|
OR |
X | Y |
Returns TRUE if either X or Y is
included, otherwise, returns FALSE.
|
AND |
X & Y |
Returns TRUE if both X and Y are
included, otherwise, returns FALSE.
|
Graph predicates
GoogleSQL supports the following graph-specific predicates in
graph expressions. A predicate can produce TRUE, FALSE, or NULL.
PROPERTY_EXISTSpredicateIS SOURCEpredicateIS DESTINATIONpredicateIS LABELEDpredicateSAMEpredicate
IS DESTINATION predicate
node IS [ NOT ] DESTINATION [ OF ] edge
Description
In a graph, checks to see if a node is or isn't the destination of an edge.
Can produce TRUE, FALSE, or NULL.
Arguments:
node: The graph pattern variable for the node element.edge: The graph pattern variable for the edge element.
Examples
GRAPH FinGraph
MATCH (a:Account)-[transfer:Transfers]-(b:Account)
WHERE a IS DESTINATION of transfer
RETURN a.id AS a_id, b.id AS b_id
/*-------------+
| a_id | b_id |
+-------------+
| 16 | 7 |
| 16 | 7 |
| 20 | 16 |
| 7 | 20 |
| 16 | 20 |
+-------------*/
GRAPH FinGraph
MATCH (a:Account)-[transfer:Transfers]-(b:Account)
WHERE b IS DESTINATION of transfer
RETURN a.id AS a_id, b.id AS b_id
/*-------------+
| a_id | b_id |
+-------------+
| 7 | 16 |
| 7 | 16 |
| 16 | 20 |
| 20 | 7 |
| 20 | 16 |
+-------------*/
IS LABELED predicate
element IS [ NOT ] LABELED label_expression
Description
In a graph, checks to see if a node or edge label satisfies a label
expression. Can produce TRUE, FALSE, or NULL if element is NULL.
Arguments:
element: The graph pattern variable for a graph node or edge element.label_expression: The label expression to verify. For more information, see Label expression definition.
Examples
GRAPH FinGraph
MATCH (a)
WHERE a IS LABELED Account | Person
RETURN a.id AS a_id, LABELS(a) AS labels
/*----------------+
| a_id | labels |
+----------------+
| 1 | Person |
| 2 | Person |
| 3 | Person |
| 7 | Account |
| 16 | Account |
| 20 | Account |
+----------------*/
GRAPH FinGraph
MATCH (a)-[e]-(b:Account)
WHERE e IS LABELED Transfers | Owns
RETURN a.Id as a_id, Labels(e) AS labels, b.Id as b_id
ORDER BY a_id, b_id
/*------+-----------------------+------+
| a_id | labels | b_id |
+------+-----------------------+------+
| 1 | [owns] | 7 |
| 2 | [owns] | 20 |
| 3 | [owns] | 16 |
| 7 | [transfers] | 16 |
| 7 | [transfers] | 16 |
| 7 | [transfers] | 20 |
| 16 | [transfers] | 7 |
| 16 | [transfers] | 7 |
| 16 | [transfers] | 20 |
| 16 | [transfers] | 20 |
| 20 | [transfers] | 7 |
| 20 | [transfers] | 16 |
| 20 | [transfers] | 16 |
+------+-----------------------+------*/
GRAPH FinGraph
MATCH (a:Account {Id: 7})
OPTIONAL MATCH (a)-[:OWNS]->(b)
RETURN a.Id AS a_id, b.Id AS b_id, b IS LABELED Account AS b_is_account
/*------+-----------------------+
| a_id | b_id | b_is_account |
+------+-----------------------+
| 7 | NULL | NULL |
+------+-----------------------+*/
IS SOURCE predicate
node IS [ NOT ] SOURCE [ OF ] edge
Description
In a graph, checks to see if a node is or isn't the source of an edge.
Can produce TRUE, FALSE, or NULL.
Arguments:
node: The graph pattern variable for the node element.edge: The graph pattern variable for the edge element.
Examples
GRAPH FinGraph
MATCH (a:Account)-[transfer:Transfers]-(b:Account)
WHERE a IS SOURCE of transfer
RETURN a.id AS a_id, b.id AS b_id
/*-------------+
| a_id | b_id |
+-------------+
| 20 | 7 |
| 7 | 16 |
| 7 | 16 |
| 20 | 16 |
| 16 | 20 |
+-------------*/
GRAPH FinGraph
MATCH (a:Account)-[transfer:Transfers]-(b:Account)
WHERE b IS SOURCE of transfer
RETURN a.id AS a_id, b.id AS b_id
/*-------------+
| a_id | b_id |
+-------------+
| 7 | 20 |
| 16 | 7 |
| 16 | 7 |
| 16 | 20 |
| 20 | 16 |
+-------------*/
PROPERTY_EXISTS predicate
PROPERTY_EXISTS(element, element_property)
Description
In a graph, checks to see if a property exists for an element.
Can produce TRUE, FALSE, or NULL.
Arguments:
element: The graph pattern variable for a node or edge element.element_property: The name of the property to look for inelement. The property name must refer to a property in the graph. If the property doesn't exist in the graph, an error is produced. The property name is resolved in a case-insensitive manner.
Example
GRAPH FinGraph
MATCH (n:Person|Account WHERE PROPERTY_EXISTS(n, name))
RETURN n.name
/*------+
| name |
+------+
| Alex |
| Dana |
| Lee |
+------*/
SAME predicate
SAME (element, element[, ...])
Description
In a graph, checks if all graph elements in a list bind to the same node or
edge. Returns TRUE if the elements bind to the same node or edge, otherwise
FALSE.
Arguments:
element: The graph pattern variable for a node or edge element.
Details
Produces an error if element is NULL.
Example
The following query checks to see if a and b aren't the same person.
GRAPH FinGraph
MATCH (src:Account)<-[transfer:Transfers]-(dest:Account)
WHERE NOT SAME(src, dest)
RETURN src.id AS source_id, dest.id AS destination_id
/*----------------------------+
| source_id | destination_id |
+----------------------------+
| 7 | 20 |
| 16 | 7 |
| 16 | 7 |
| 16 | 20 |
| 20 | 16 |
+----------------------------*/
Comparison operators
Compares operands and produces the results of the comparison as a BOOL
value. These comparison operators are available:
| Name | Syntax | Description |
|---|---|---|
| Less Than | X < Y |
Returns TRUE if X is less than Y.
This operator supports specifying collation.
This operator supports specifying collation.
This operator supports specifying collation.
This operator supports specifying collation.
This operator supports specifying collation.
This operator supports specifying collation.
This operator supports specifying collation.
|
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.
- Comparisons between operands that are signed and unsigned integers is allowed.
- Struct operands support only these comparison operators: equal
(
=), not equal (!=and<>), andIN.
The following rules apply when comparing these data types:
-
Floating point: All comparisons with
NaNreturnFALSE, except for!=and<>, which returnTRUE. -
BOOL:FALSEis less thanTRUE. -
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, seeJSONfunctions. -
NULL: Any operation with aNULLinput returnsNULL. -
STRUCT: When testing a struct for equality, it's possible that one or more fields areNULL. In such cases:- If all non-
NULLfield values are equal, the comparison returnsNULL. - If any non-
NULLfield values aren't equal, the comparison returnsFALSE.
The following table demonstrates how
STRUCTdata types are compared when they have fields that areNULLvalued.Struct1 Struct2 Struct1 = Struct2 STRUCT(1, NULL)STRUCT(1, NULL)NULLSTRUCT(1, NULL)STRUCT(2, NULL)FALSESTRUCT(1,2)STRUCT(1, NULL)NULL - If all non-
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 UNNESTdoesn'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
FALSEifvalue_setis empty. - Returns
NULLifsearch_valueisNULL. - Returns
TRUEifvalue_setcontains a value equal tosearch_value. - Returns
NULLifvalue_setcontains aNULL. - Returns
FALSE.
When using the NOT IN operator, the following semantics apply in this order:
- Returns
TRUEifvalue_setis empty. - Returns
NULLifsearch_valueisNULL. - Returns
FALSEifvalue_setcontains a value equal tosearch_value. - Returns
NULLifvalue_setcontains aNULL. - 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.
| Function Syntax | Input Data Type | Result Data Type | Description |
|---|---|---|---|
X IS TRUE |
BOOL |
BOOL |
Evaluates to TRUE if X evaluates to
TRUE.
Otherwise, evaluates to FALSE.
|
X IS NOT TRUE |
BOOL |
BOOL |
Evaluates to FALSE if X evaluates to
TRUE.
Otherwise, evaluates to TRUE.
|
X IS FALSE |
BOOL |
BOOL |
Evaluates to TRUE if X evaluates to
FALSE.
Otherwise, evaluates to FALSE.
|
X IS NOT FALSE |
BOOL |
BOOL |
Evaluates to FALSE if X evaluates to
FALSE.
Otherwise, evaluates to TRUE.
|
X IS NULL |
Any value type | BOOL |
Evaluates to TRUE if X evaluates to
NULL.
Otherwise evaluates to FALSE.
|
X IS NOT NULL |
Any value type | BOOL |
Evaluates to FALSE if X evaluates to
NULL.
Otherwise evaluates to TRUE.
|
X IS UNKNOWN |
BOOL |
BOOL |
Evaluates to TRUE if X evaluates to
NULL.
Otherwise evaluates to FALSE.
|
X IS NOT UNKNOWN |
BOOL |
BOOL |
Evaluates to FALSE if X evaluates to
NULL.
Otherwise, evaluates to TRUE.
|
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]) xreturning2.SELECT * FROM UNNEST([a,b]) x GROUP BY xreturning 2 rows.
a IS DISTINCT FROM b is equivalent to NOT (a = b), except for the
following cases:
- This operator never returns
NULLsoNULLvalues are considered to be distinct from non-NULLvalues, not otherNULLvalues. NaNvalues are considered to be distinct from non-NaNvalues, but not otherNaNvalues.
Input values:
expression_1: The first value to compare. This can be a groupable data type,NULLorNaN.expression_2: The second value to compare. This can be a groupable data type,NULLorNaN.NOT: If present, the outputBOOLvalue 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 inexpression_2represents an arbitrary string specifier. An arbitrary string specifier can represent any sequence of0or 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'tund: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 inexpression_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:cicollator doesn't fully normalize a string. Some canonically equivalent strings are considered unequal for both the=andLIKEoperators. -
The
LIKEoperator 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\U00DFss
\u1E9Eand\U00DFare considered equal but differ in tertiary. They are considered equal withund:cicollation but different fromss, 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 ARRAY_INCLUDES(['%ity%', '%and%'], pattern->(Words.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:
{
(expression[, ...])
(subquery)
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 aSTRINGorBYTEStype. -
patterns: The patterns to look for in the search value. Each pattern must resolve to the same type assearch_value. Each pattern is one of the following:- A list of one or more patterns that match the
search_valuetype.
- A list of one or more patterns that match the
-
A subquery that returns a single column with the same type as
search_value. -
An
UNNESToperation that returns a column of values with the same type assearch_valuefrom 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 forANY. -
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
LIKEoperator also apply to the quantifiedLIKEoperator. - 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
FALSEifpatternsis empty. - Returns
NULLifsearch_valueisNULL. - Returns
TRUEsearch_value LIKE patternisTRUEfor at least one value inpatterns. - Returns
NULLif a pattern inpatternsisNULL. - Returns
FALSE.
When using the quantified LIKE operator with ALL, the following semantics
apply in this order:
- Returns
TRUEifpatternsis empty. - Returns
NULLifsearch_valueisNULL. - Returns
FALSEifsearch_value LIKE patternisFALSEfor at least one value inpatterns. - Returns
NULLif a pattern inpatternsisNULL. - Returns
TRUE.
When using the quantified NOT LIKE operator with ANY or SOME, the
following semantics apply in this order:
- Returns
FALSEifpatternsis empty. - Returns
NULLifsearch_valueisNULL. - Returns
TRUEifsearch_value LIKE patternisFALSEfor at least one value inpatterns. - Returns
NULLif a pattern inpatternsisNULL. - Returns
FALSE.
When using the quantified NOT LIKE operator with ALL, the following
semantics apply in this order:
- Returns
TRUEifpatternsis empty. - For
pattern_array, returnsTRUEifpatternsis empty. - Returns
NULLifsearch_valueisNULL. - Returns
FALSEifsearch_value LIKE patternisTRUEfor at least one value inpatterns. - Returns
NULLif a pattern inpatternsisNULL. - Returns
TRUE.
Return Data Type
BOOL
Examples
You can use these WITH clauses to emulate temporary tables for
Words in the following examples:
WITH Words AS
(SELECT 'Intend with clarity.' as value UNION ALL
SELECT 'Secure with intention.' UNION ALL
SELECT 'Clarity and security.')
/*------------------------+
| value |
+------------------------+
| Intend with clarity. |
| Secure with intention. |
| Clarity and security. |
+------------------------*/
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:
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:
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:
SELECT * FROM Words WHERE value NOT LIKE ('%ity%');
/*------------------------+
| value |
+------------------------+
| Secure with intention. |
+------------------------*/
You can use a subquery as an expression in patterns. For example:
SELECT * FROM Words WHERE value LIKE ANY ((SELECT '%ion%'), '%and%');
/*------------------------+
| value |
+------------------------+
| Secure with intention. |
| Clarity and security. |
+------------------------*/
You can pass in a subquery for patterns. For example:
SELECT * FROM Words WHERE value LIKE ANY (SELECT '%with%');
/*------------------------+
| value |
+------------------------+
| Intend with clarity. |
| Secure with intention. |
+------------------------*/
You can pass in an array for patterns. For example:
SELECT * FROM Words WHERE value LIKE ANY UNNEST(['%ion%', '%and%']);
/*------------------------+
| value |
+------------------------+
| Secure with intention. |
| Clarity and security. |
+------------------------*/
You can pass in an array and subquery for patterns. For example:
SELECT *
FROM Words
WHERE
value LIKE ANY UNNEST(ARRAY(SELECT e FROM UNNEST(['%ion%', '%and%']) AS e));
/*------------------------+
| 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');
NEW operator
The NEW operator only supports protocol buffers and uses the following syntax:
NEW protocol_buffer {...}: Creates a protocol buffer using a map constructor.
NEW protocol_buffer {
field_name: literal_or_expression
field_name { ... }
repeated_field_name: [literal_or_expression, ... ]
}
-
NEW protocol_buffer (...): Creates a protocol buffer using a parenthesized list of arguments.NEW protocol_buffer(field [AS alias], ...field [AS alias])
Examples
The following example uses the NEW operator with a map constructor:
NEW Universe {
name: "Sol"
closest_planets: ["Mercury", "Venus", "Earth" ]
star {
radius_miles: 432,690
age: 4,603,000,000
}
constellations: [{
name: "Libra"
index: 0
}, {
name: "Scorpio"
index: 1
}]
all_planets: (SELECT planets FROM SolTable)
}
The following example uses the NEW operator with a parenthesized list of
arguments:
SELECT
key,
name,
NEW googlesql.examples.music.Chart(key AS rank, name AS chart_name)
FROM
(SELECT 1 AS key, "2" AS name);
To learn more about protocol buffers in GoogleSQL, see Work with protocol buffers.
Concatenation operator
The concatenation operator combines multiple values into one.
| Function Syntax | Input Data Type | Result Data Type |
|---|---|---|
STRING || STRING [ || ... ] |
STRING |
STRING |
BYTES || BYTES [ || ... ] |
BYTES |
BYTES |
ARRAY<T> || ARRAY<T> [ || ... ] |
ARRAY<T> |
ARRAY<T> |
Note: The concatenation operator is translated into a nested
CONCAT function call. For example, 'A' || 'B' || 'C' becomes
CONCAT('A', CONCAT('B', 'C')).
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 givenWITHexpression. Each expression can reference the variables that come before it. For example, if you create variablea, then follow it with variableb, then you can referenceainside of the expression forb.-
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 ofresult_expressionis returned by theWITHexpression.
Return Type
- The type of the
result_expression.
Requirements and Caveats
- A variable can only be assigned once within a
WITHexpression. - Variables created during
WITHmay 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 |
+-------+-------*/