Aggregate functions

GoogleSQL for Bigtable supports the following general aggregate functions. To learn about the syntax for aggregate function calls, see Aggregate function calls .

Function list

Name Summary
ANY_VALUE Gets an expression for some row.
APPROX_COUNT_DISTINCT Gets the approximate result for COUNT(DISTINCT expression) .
For more information, see Approximate aggregate functions .
APPROX_QUANTILES Gets the approximate quantile boundaries.
For more information, see Approximate aggregate functions .
APPROX_TOP_COUNT Gets the approximate top elements and their approximate count.
For more information, see Approximate aggregate functions .
APPROX_TOP_SUM Gets the approximate top elements and sum, based on the approximate sum of an assigned weight.
For more information, see Approximate aggregate functions .
ARRAY_AGG Gets an array of values.
ARRAY_CONCAT_AGG Concatenates arrays and returns a single array as a result.
AVG Gets the average of non- NULL values.
BIT_AND Performs a bitwise AND operation on an expression.
BIT_OR Performs a bitwise OR operation on an expression.
BIT_XOR Performs a bitwise XOR operation on an expression.
CORR Computes the Pearson coefficient of correlation of a set of number pairs.
For more information, see Statistical aggregate functions .
COUNT Gets the number of rows in the input, or the number of rows with an expression evaluated to any value other than NULL .
COUNTIF Gets the number of TRUE values for an expression.
COVAR_POP Computes the population covariance of a set of number pairs.
For more information, see Statistical aggregate functions .
COVAR_SAMP Computes the sample covariance of a set of number pairs.
For more information, see Statistical aggregate functions .
LOGICAL_AND Gets the logical AND of all non- NULL expressions.
LOGICAL_OR Gets the logical OR of all non- NULL expressions.
MAX Gets the maximum non- NULL value.
MIN Gets the minimum non- NULL value.
STDDEV An alias of the STDDEV_SAMP function.
For more information, see Statistical aggregate functions .
STDDEV_POP Computes the population (biased) standard deviation of the values.
For more information, see Statistical aggregate functions .
STDDEV_SAMP Computes the sample (unbiased) standard deviation of the values.
For more information, see Statistical aggregate functions .
STRING_AGG Concatenates non- NULL STRING or BYTES values.
SUM Gets the sum of non- NULL values.
VAR_POP Computes the population (biased) variance of the values.
For more information, see Statistical aggregate functions .
VAR_SAMP Computes the sample (unbiased) variance of the values.
For more information, see Statistical aggregate functions .
VARIANCE An alias of VAR_SAMP .
For more information, see Statistical aggregate functions .

ANY_VALUE

  ANY_VALUE 
 ( 
  
 expression 
 ) 
 

Description

Returns expression for some row chosen from the group. Which row is chosen is nondeterministic, not random. Returns NULL when the input produces no rows. Returns NULL when expression is NULL for all rows in the group.

ANY_VALUE behaves as if RESPECT NULLS is specified; rows for which expression is NULL are considered and may be selected. Some engines make a best effort to select non- NULL values whenever possible.

To learn more about the optional aggregate clauses that you can pass into this function, see Aggregate function calls .

Supported Argument Types

Any

Returned Data Types

Matches the input data type.

Examples

  SELECT 
  
 ANY_VALUE 
 ( 
 fruit 
 ) 
  
 as 
  
 any_value 
 FROM 
  
 UNNEST 
 ( 
 [ 
 "apple" 
 , 
  
 "banana" 
 , 
  
 "pear" 
 ] 
 ) 
  
 as 
  
 fruit 
 ; 
 /*-----------* 
 | any_value | 
 +-----------+ 
 | apple     | 
 *-----------*/ 
 

ARRAY_AGG

  ARRAY_AGG 
 ( 
  
 [ 
  
 DISTINCT 
  
 ] 
  
 expression 
 ) 
 

Description

Returns an ARRAY of expression values.

To learn more about the optional aggregate clauses that you can pass into this function, see Aggregate function calls .

Supported Argument Types

All data types except ARRAY.

Returned Data Types

ARRAY

If there are zero input rows, this function returns NULL .

Examples

  SELECT 
  
 ARRAY_AGG 
 ( 
 x 
 ) 
  
 AS 
  
 array_agg 
  
 FROM 
  
 UNNEST 
 ( 
 [ 
 2 
 , 
  
 1 
 , 
 - 
 2 
 , 
  
 3 
 , 
  
 - 
 2 
 , 
  
 1 
 , 
  
 2 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*-------------------------* 
 | array_agg               | 
 +-------------------------+ 
 | [2, 1, -2, 3, -2, 1, 2] | 
 *-------------------------*/ 
 
  SELECT 
  
 ARRAY_AGG 
 ( 
 DISTINCT 
  
 x 
 ) 
  
 AS 
  
 array_agg 
 FROM 
  
 UNNEST 
 ( 
 [ 
 2 
 , 
  
 1 
 , 
  
 - 
 2 
 , 
  
 3 
 , 
  
 - 
 2 
 , 
  
 1 
 , 
  
 2 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*---------------* 
 | array_agg     | 
 +---------------+ 
 | [2, 1, -2, 3] | 
 *---------------*/ 
 
  SELECT 
  
 x 
 , 
  
 ARRAY_AGG 
 ( 
 y 
 ) 
  
 AS 
  
 array_agg 
 FROM 
  
 UNNEST 
 ( 
  
 ARRAY<STRUCT<x 
  
 INT64 
 , 
  
 y 
  
 STRING 
>> [ 
 ( 
 1 
 , 
  
 'a' 
 ), 
  
 ( 
 1 
 , 
  
 'b' 
 ), 
  
 ( 
 2 
 , 
  
 'a' 
 ), 
  
 ( 
 2 
 , 
  
 'c' 
 ) 
 ] 
 ) 
 GROUP 
  
 BY 
  
 x 
 ; 
 /*---------------* 
 | x | array_agg | 
 +---------------+ 
 | 1 | [a, b]    | 
 | 2 | [a, c]    | 
 *---------------*/ 
 

ARRAY_CONCAT_AGG

  ARRAY_CONCAT_AGG 
 ( 
  
 expression 
 ) 
 

Description

Concatenates elements from expression of type ARRAY , returning a single array as a result.

This function ignores NULL input arrays, but respects the NULL elements in non- NULL input arrays. Returns NULL if there are zero input rows or expression evaluates to NULL for all rows.

To learn more about the optional aggregate clauses that you can pass into this function, see Aggregate function calls .

Supported Argument Types

ARRAY

Returned Data Types

ARRAY

Examples

  SELECT 
  
 FORMAT 
 ( 
 "%T" 
 , 
  
 ARRAY_CONCAT_AGG 
 ( 
 x 
 )) 
  
 AS 
  
 array_concat_agg 
  
 FROM 
  
 ( 
  
 SELECT 
  
 [ 
 NULL 
 , 
  
 1 
 , 
  
 2 
 , 
  
 3 
 , 
  
 4 
 ] 
  
 AS 
  
 x 
  
 UNION 
  
 ALL 
  
 SELECT 
  
 NULL 
  
 UNION 
  
 ALL 
  
 SELECT 
  
 [ 
 5 
 , 
  
 6 
 ] 
  
 UNION 
  
 ALL 
  
 SELECT 
  
 [ 
 7 
 , 
  
 8 
 , 
  
 9 
 ] 
 ); 
 /*-----------------------------------* 
 | array_concat_agg                  | 
 +-----------------------------------+ 
 | [NULL, 1, 2, 3, 4, 5, 6, 7, 8, 9] | 
 *-----------------------------------*/ 
 

AVG

  AVG 
 ( 
  
 [ 
  
 DISTINCT 
  
 ] 
  
 expression 
 ) 
 

Description

Returns the average of non- NULL values in an aggregated group.

To learn more about the optional aggregate clauses that you can pass into this function, see Aggregate function calls .

Caveats:

  • If the aggregated group is empty or the argument is NULL for all rows in the group, returns NULL .
  • If the argument is NaN for any row in the group, returns NaN .
  • If the argument is [+|-]Infinity for any row in the group, returns either [+|-]Infinity or NaN .
  • If there is numeric overflow, produces an error.
  • If a floating-point type is returned, the result is non-deterministic , which means you might receive a different result each time you use this function.

Supported Argument Types

  • Any numeric input type

Returned Data Types

INPUT INT64 FLOAT32 FLOAT64
OUTPUT
FLOAT64 FLOAT64 FLOAT64

Examples

  SELECT 
  
 AVG 
 ( 
 x 
 ) 
  
 as 
  
 avg 
 FROM 
  
 UNNEST 
 ( 
 [ 
 0 
 , 
  
 2 
 , 
  
 4 
 , 
  
 4 
 , 
  
 5 
 ] 
 ) 
  
 as 
  
 x 
 ; 
 /*-----* 
 | avg | 
 +-----+ 
 | 3   | 
 *-----*/ 
 
  SELECT 
  
 AVG 
 ( 
 DISTINCT 
  
 x 
 ) 
  
 AS 
  
 avg 
 FROM 
  
 UNNEST 
 ( 
 [ 
 0 
 , 
  
 2 
 , 
  
 4 
 , 
  
 4 
 , 
  
 5 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*------* 
 | avg  | 
 +------+ 
 | 2.75 | 
 *------*/ 
 

BIT_AND

  BIT_AND 
 ( 
  
 expression 
 ) 
 

Description

Performs a bitwise AND operation on expression and returns the result.

To learn more about the optional aggregate clauses that you can pass into this function, see Aggregate function calls .

Supported Argument Types

  • INT64

Returned Data Types

INT64

Examples

  SELECT 
  
 BIT_AND 
 ( 
 x 
 ) 
  
 as 
  
 bit_and 
  
 FROM 
  
 UNNEST 
 ( 
 [ 
 0xF001 
 , 
  
 0x00A1 
 ] 
 ) 
  
 as 
  
 x 
 ; 
 /*---------* 
 | bit_and | 
 +---------+ 
 | 1       | 
 *---------*/ 
 

BIT_OR

  BIT_OR 
 ( 
  
 expression 
 ) 
 

Description

Performs a bitwise OR operation on expression and returns the result.

To learn more about the optional aggregate clauses that you can pass into this function, see Aggregate function calls .

Supported Argument Types

  • INT64

Returned Data Types

INT64

Examples

  SELECT 
  
 BIT_OR 
 ( 
 x 
 ) 
  
 as 
  
 bit_or 
  
 FROM 
  
 UNNEST 
 ( 
 [ 
 0xF001 
 , 
  
 0x00A1 
 ] 
 ) 
  
 as 
  
 x 
 ; 
 /*--------* 
 | bit_or | 
 +--------+ 
 | 61601  | 
 *--------*/ 
 

BIT_XOR

  BIT_XOR 
 ( 
  
 [ 
  
 DISTINCT 
  
 ] 
  
 expression 
 ) 
 

Description

Performs a bitwise XOR operation on expression and returns the result.

To learn more about the optional aggregate clauses that you can pass into this function, see Aggregate function calls .

Supported Argument Types

  • INT64

Returned Data Types

INT64

Examples

  SELECT 
  
 BIT_XOR 
 ( 
 x 
 ) 
  
 AS 
  
 bit_xor 
  
 FROM 
  
 UNNEST 
 ( 
 [ 
 5678 
 , 
  
 1234 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*---------* 
 | bit_xor | 
 +---------+ 
 | 4860    | 
 *---------*/ 
 
  SELECT 
  
 BIT_XOR 
 ( 
 x 
 ) 
  
 AS 
  
 bit_xor 
  
 FROM 
  
 UNNEST 
 ( 
 [ 
 1234 
 , 
  
 5678 
 , 
  
 1234 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*---------* 
 | bit_xor | 
 +---------+ 
 | 5678    | 
 *---------*/ 
 
  SELECT 
  
 BIT_XOR 
 ( 
 DISTINCT 
  
 x 
 ) 
  
 AS 
  
 bit_xor 
  
 FROM 
  
 UNNEST 
 ( 
 [ 
 1234 
 , 
  
 5678 
 , 
  
 1234 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*---------* 
 | bit_xor | 
 +---------+ 
 | 4860    | 
 *---------*/ 
 

COUNT

  COUNT 
 ( 
 * 
 ) 
 
  COUNT 
 ( 
  
 [ 
  
 DISTINCT 
  
 ] 
  
 expression 
 ) 
 

Description

Gets the number of rows in the input or the number of rows with an expression evaluated to any value other than NULL .

Definitions

  • * : Use this value to get the number of all rows in the input.
  • expression : A value of any data type that represents the expression to evaluate. If DISTINCT is present, expression can only be a data type that is groupable .
  • DISTINCT : To learn more, see Aggregate function calls .

Details

To count the number of distinct values of an expression for which a certain condition is satisfied, you can use the following recipe:

  COUNT 
 ( 
 DISTINCT 
  
 IF 
 ( 
 condition 
 , 
  
 expression 
 , 
  
 NULL 
 )) 
 

IF returns the value of expression if condition is TRUE , or NULL otherwise. The surrounding COUNT(DISTINCT ...) ignores the NULL values, so it counts only the distinct values of expression for which condition is TRUE .

To count the number of non-distinct values of an expression for which a certain condition is satisfied, consider using the COUNTIF function.

This function with DISTINCT supports specifying collation .

Return type

INT64

Examples

You can use the COUNT function to return the number of rows in a table or the number of distinct values of an expression. For example:

  SELECT 
  
 COUNT 
 ( 
 * 
 ) 
  
 AS 
  
 count_star 
 , 
  
 COUNT 
 ( 
 DISTINCT 
  
 x 
 ) 
  
 AS 
  
 count_dist_x 
 FROM 
  
 UNNEST 
 ( 
 [ 
 1 
 , 
  
 4 
 , 
  
 4 
 , 
  
 5 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*------------+--------------* 
 | count_star | count_dist_x | 
 +------------+--------------+ 
 | 4          | 3            | 
 *------------+--------------*/ 
 
  SELECT 
  
 COUNT 
 ( 
 * 
 ) 
  
 AS 
  
 count_star 
 , 
  
 COUNT 
 ( 
 x 
 ) 
  
 AS 
  
 count_x 
 FROM 
  
 UNNEST 
 ( 
 [ 
 1 
 , 
  
 4 
 , 
  
 NULL 
 , 
  
 4 
 , 
  
 5 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*------------+---------* 
 | count_star | count_x | 
 +------------+---------+ 
 | 5          | 4       | 
 *------------+---------*/ 
 

The following query counts the number of distinct positive values of x :

  SELECT 
  
 COUNT 
 ( 
 DISTINCT 
  
 IF 
 ( 
 x 
 > 
 0 
 , 
  
 x 
 , 
  
 NULL 
 )) 
  
 AS 
  
 distinct_positive 
 FROM 
  
 UNNEST 
 ( 
 [ 
 1 
 , 
  
 - 
 2 
 , 
  
 4 
 , 
  
 1 
 , 
  
 - 
 5 
 , 
  
 4 
 , 
  
 1 
 , 
  
 3 
 , 
  
 - 
 6 
 , 
  
 1 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*-------------------* 
 | distinct_positive | 
 +-------------------+ 
 | 3                 | 
 *-------------------*/ 
 

The following query counts the number of distinct dates on which a certain kind of event occurred:

  SELECT 
  
 COUNT 
 ( 
 DISTINCT 
  
 IF 
 ( 
 event_type 
  
 = 
  
 'FAILURE' 
 , 
  
 event_date 
 , 
  
 NULL 
 )) 
  
 AS 
  
 distinct_dates_with_failures 
 FROM 
  
 UNNEST 
 ( 
  
 ARRAY<STRUCT<event_date 
  
 DATE 
 , 
  
 event_type 
  
 STRING 
>> [ 
  
 ( 
 DATE 
  
 '2021-01-01' 
 , 
  
 'SUCCESS' 
 ), 
  
 ( 
 DATE 
  
 '2021-01-02' 
 , 
  
 'SUCCESS' 
 ), 
  
 ( 
 DATE 
  
 '2021-01-02' 
 , 
  
 'FAILURE' 
 ), 
  
 ( 
 DATE 
  
 '2021-01-03' 
 , 
  
 'SUCCESS' 
 ), 
  
 ( 
 DATE 
  
 '2021-01-04' 
 , 
  
 'FAILURE' 
 ), 
  
 ( 
 DATE 
  
 '2021-01-04' 
 , 
  
 'FAILURE' 
 ) 
 ] 
 ) 
  
 AS 
  
 Events 
 ; 
 /*------------------------------* 
 | distinct_dates_with_failures | 
 +------------------------------+ 
 | 2                            | 
 *------------------------------*/ 
 

The following query counts the number of distinct id s that exist in both the customers and vendor tables:

  SELECT 
  
 COUNT 
 ( 
  
 DISTINCT 
  
 IF 
 ( 
  
 id 
  
 IN 
  
 ( 
  
 SELECT 
  
 id 
  
 FROM 
  
 UNNEST 
 ( 
  
 ARRAY<STRUCT<id 
  
 INT64 
 , 
  
 team 
  
 STRING 
>> [ 
  
 ( 
 1934 
 , 
  
 'a' 
 ), 
  
 ( 
 2991 
 , 
  
 'b' 
 ), 
  
 ( 
 3988 
 , 
  
 'c' 
 ) 
 ] 
 ) 
  
 AS 
  
 customers 
  
 ), 
  
 id 
 , 
  
 NULL 
 )) 
  
 AS 
  
 result 
 FROM 
  
 UNNEST 
 ( 
  
 ARRAY<STRUCT<id 
  
 INT64 
 , 
  
 team 
  
 STRING 
>> [ 
  
 ( 
 1934 
 , 
  
 'd' 
 ), 
  
 ( 
 2991 
 , 
  
 'e' 
 ), 
  
 ( 
 4366 
 , 
  
 'f' 
 ) 
 ] 
 ) 
  
 AS 
  
 vendors 
 /*--------* 
 | result | 
 +--------+ 
 | 2      | 
 *--------*/ 
 

COUNTIF

  COUNTIF 
 ( 
  
 [ 
  
 DISTINCT 
  
 ] 
  
 expression 
 ) 
 

Description

Gets the number of TRUE values for an expression.

Definitions

  • expression : A BOOL value that represents the expression to evaluate.
  • DISTINCT : To learn more, see Aggregate function calls .

Details

The function signature COUNTIF(DISTINCT ...) is generally not useful. If you would like to use DISTINCT , use COUNT with DISTINCT IF . For more information, see the COUNT function.

Return type

INT64

Examples

  SELECT 
  
 COUNTIF 
 ( 
 x<0 
 ) 
  
 AS 
  
 num_negative 
 , 
  
 COUNTIF 
 ( 
 x>0 
 ) 
  
 AS 
  
 num_positive 
 FROM 
  
 UNNEST 
 ( 
 [ 
 5 
 , 
  
 - 
 2 
 , 
  
 3 
 , 
  
 6 
 , 
  
 - 
 10 
 , 
  
 - 
 7 
 , 
  
 4 
 , 
  
 0 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*--------------+--------------* 
 | num_negative | num_positive | 
 +--------------+--------------+ 
 | 3            | 4            | 
 *--------------+--------------*/ 
 

LOGICAL_AND

  LOGICAL_AND 
 ( 
  
 expression 
 ) 
 

Description

Returns the logical AND of all non- NULL expressions. Returns NULL if there are zero input rows or expression evaluates to NULL for all rows.

To learn more about the optional aggregate clauses that you can pass into this function, see Aggregate function calls .

Supported Argument Types

BOOL

Return Data Types

BOOL

Examples

LOGICAL_AND returns FALSE because not all of the values in the array are less than 3.

  SELECT 
  
 LOGICAL_AND 
 ( 
 x 
 < 
 3 
 ) 
  
 AS 
  
 logical_and 
  
 FROM 
  
 UNNEST 
 ( 
 [ 
 1 
 , 
  
 2 
 , 
  
 4 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*-------------* 
 | logical_and | 
 +-------------+ 
 | FALSE       | 
 *-------------*/ 
 

LOGICAL_OR

  LOGICAL_OR 
 ( 
  
 expression 
 ) 
 

Description

Returns the logical OR of all non- NULL expressions. Returns NULL if there are zero input rows or expression evaluates to NULL for all rows.

To learn more about the optional aggregate clauses that you can pass into this function, see Aggregate function calls .

Supported Argument Types

BOOL

Return Data Types

BOOL

Examples

LOGICAL_OR returns TRUE because at least one of the values in the array is less than 3.

  SELECT 
  
 LOGICAL_OR 
 ( 
 x 
 < 
 3 
 ) 
  
 AS 
  
 logical_or 
  
 FROM 
  
 UNNEST 
 ( 
 [ 
 1 
 , 
  
 2 
 , 
  
 4 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*------------* 
 | logical_or | 
 +------------+ 
 | TRUE       | 
 *------------*/ 
 

MAX

  MAX 
 ( 
  
 expression 
 ) 
 

Description

Returns the maximum non- NULL value in an aggregated group.

Caveats:

  • If the aggregated group is empty or the argument is NULL for all rows in the group, returns NULL .
  • If the argument is NaN for any row in the group, returns NaN .

To learn more about the optional aggregate clauses that you can pass into this function, see Aggregate function calls .

This function supports specifying collation .

Supported Argument Types

Any orderable data type except for ARRAY .

Return Data Types

The data type of the input values.

Examples

  SELECT 
  
 MAX 
 ( 
 x 
 ) 
  
 AS 
  
 max 
 FROM 
  
 UNNEST 
 ( 
 [ 
 8 
 , 
  
 37 
 , 
  
 55 
 , 
  
 4 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*-----* 
 | max | 
 +-----+ 
 | 55  | 
 *-----*/ 
 

MIN

  MIN 
 ( 
  
 expression 
 ) 
 

Description

Returns the minimum non- NULL value in an aggregated group.

Caveats:

  • If the aggregated group is empty or the argument is NULL for all rows in the group, returns NULL .
  • If the argument is NaN for any row in the group, returns NaN .

To learn more about the optional aggregate clauses that you can pass into this function, see Aggregate function calls .

This function supports specifying collation .

Supported Argument Types

Any orderable data type except for ARRAY .

Return Data Types

The data type of the input values.

Examples

  SELECT 
  
 MIN 
 ( 
 x 
 ) 
  
 AS 
  
 min 
 FROM 
  
 UNNEST 
 ( 
 [ 
 8 
 , 
  
 37 
 , 
  
 4 
 , 
  
 55 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*-----* 
 | min | 
 +-----+ 
 | 4   | 
 *-----*/ 
 

STRING_AGG

  STRING_AGG 
 ( 
  
 [ 
  
 DISTINCT 
  
 ] 
  
 expression 
  
 [ 
 , 
  
 delimiter 
 ] 
 ) 
 

Description

Returns a value (either STRING or BYTES ) obtained by concatenating non- NULL values. Returns NULL if there are zero input rows or expression evaluates to NULL for all rows.

If a delimiter is specified, concatenated values are separated by that delimiter; otherwise, a comma is used as a delimiter.

To learn more about the optional aggregate clauses that you can pass into this function, see Aggregate function calls .

Supported Argument Types

Either STRING or BYTES .

Return Data Types

Either STRING or BYTES .

Examples

  SELECT 
  
 STRING_AGG 
 ( 
 fruit 
 ) 
  
 AS 
  
 string_agg 
 FROM 
  
 UNNEST 
 ( 
 [ 
 "apple" 
 , 
  
 NULL 
 , 
  
 "pear" 
 , 
  
 "banana" 
 , 
  
 "pear" 
 ] 
 ) 
  
 AS 
  
 fruit 
 ; 
 /*------------------------* 
 | string_agg             | 
 +------------------------+ 
 | apple,pear,banana,pear | 
 *------------------------*/ 
 
  SELECT 
  
 STRING_AGG 
 ( 
 fruit 
 , 
  
 " & " 
 ) 
  
 AS 
  
 string_agg 
 FROM 
  
 UNNEST 
 ( 
 [ 
 "apple" 
 , 
  
 "pear" 
 , 
  
 "banana" 
 , 
  
 "pear" 
 ] 
 ) 
  
 AS 
  
 fruit 
 ; 
 /*------------------------------* 
 | string_agg                   | 
 +------------------------------+ 
 | apple & pear & banana & pear | 
 *------------------------------*/ 
 
  SELECT 
  
 STRING_AGG 
 ( 
 DISTINCT 
  
 fruit 
 , 
  
 " & " 
 ) 
  
 AS 
  
 string_agg 
 FROM 
  
 UNNEST 
 ( 
 [ 
 "apple" 
 , 
  
 "pear" 
 , 
  
 "banana" 
 , 
  
 "pear" 
 ] 
 ) 
  
 AS 
  
 fruit 
 ; 
 /*-----------------------* 
 | string_agg            | 
 +-----------------------+ 
 | apple & pear & banana | 
 *-----------------------*/ 
 

SUM

  SUM 
 ( 
  
 [ 
  
 DISTINCT 
  
 ] 
  
 expression 
 ) 
 

Description

Returns the sum of non- NULL values in an aggregated group.

To learn more about the optional aggregate clauses that you can pass into this function, see Aggregate function calls .

Caveats:

  • If the aggregated group is empty or the argument is NULL for all rows in the group, returns NULL .
  • If the argument is NaN for any row in the group, returns NaN .
  • If the argument is [+|-]Infinity for any row in the group, returns either [+|-]Infinity or NaN .
  • If there is numeric overflow, produces an error.
  • If a floating-point type is returned, the result is non-deterministic , which means you might receive a different result each time you use this function.

Supported Argument Types

  • Any supported numeric data type

Return Data Types

INPUT INT64 FLOAT32 FLOAT64
OUTPUT
INT64 FLOAT64 FLOAT64

Examples

  SELECT 
  
 SUM 
 ( 
 x 
 ) 
  
 AS 
  
 sum 
 FROM 
  
 UNNEST 
 ( 
 [ 
 1 
 , 
  
 2 
 , 
  
 3 
 , 
  
 4 
 , 
  
 5 
 , 
  
 4 
 , 
  
 3 
 , 
  
 2 
 , 
  
 1 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*-----* 
 | sum | 
 +-----+ 
 | 25  | 
 *-----*/ 
 
  SELECT 
  
 SUM 
 ( 
 DISTINCT 
  
 x 
 ) 
  
 AS 
  
 sum 
 FROM 
  
 UNNEST 
 ( 
 [ 
 1 
 , 
  
 2 
 , 
  
 3 
 , 
  
 4 
 , 
  
 5 
 , 
  
 4 
 , 
  
 3 
 , 
  
 2 
 , 
  
 1 
 ] 
 ) 
  
 AS 
  
 x 
 ; 
 /*-----* 
 | sum | 
 +-----+ 
 | 15  | 
 *-----*/ 
 
  SELECT 
  
 SUM 
 ( 
 x 
 ) 
  
 AS 
  
 sum 
 FROM 
  
 UNNEST 
 ( 
 [] 
 ) 
  
 AS 
  
 x 
 ; 
 /*------* 
 | sum  | 
 +------+ 
 | NULL | 
 *------*/ 
 
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