GROUPING_ID¶

Syntax¶

GROUPING_ID( <expr1> [ , <expr2> , ... ] ) 

Usage notes¶

GROUPING_ID is not an aggregate function, but rather a utility function that can be used alongside aggregation, to determine the level of aggregation a row was generated for:

• GROUPING_ID(expr) returns 0 for a row that is grouped on expr, and 1 for a row that is not grouped on expr.

• GROUPING_ID(expr1, expr2 , … , exprN) returns the integer representation of a bit-vector containing GROUPING_ID(expr1) , GROUPING_ID(expr2) , … , GROUPING_ID(exprN).

Examples¶

The examples use the following table and data:

CREATE OR REPLACE TABLE aggr2(col_x int, col_y int, col_z int); INSERT INTO aggr2 VALUES (1, 2, 1), (1, 2, 3); INSERT INTO aggr2 VALUES (2, 1, 10), (2, 2, 11), (2, 2, 3); 

Copy

This example groups on col_x. Calling GROUPING_ID(col_x) returns 0, indicating that col_x is indeed one of the grouping columns.

SELECT col_x, sum(col_z), GROUPING_ID(col_x) FROM aggr2 GROUP BY col_x ORDER BY col_x; +-------+------------+--------------------+ | COL_X | SUM(COL_Z) | GROUPING_ID(COL_X) | |-------+------------+--------------------| | 1 | 4 | 0 | | 2 | 24 | 0 | +-------+------------+--------------------+ 

Copy

This query groups by sets:

SELECT col_x, col_y, sum(col_z), GROUPING_ID(col_x), GROUPING_ID(col_y), GROUPING_ID(col_x, col_y) FROM aggr2 GROUP BY GROUPING SETS ((col_x), (col_y), ()) ORDER BY col_x ASC, col_y DESC; +-------+-------+------------+--------------------+--------------------+---------------------------+ | COL_X | COL_Y | SUM(COL_Z) | GROUPING_ID(COL_X) | GROUPING_ID(COL_Y) | GROUPING_ID(COL_X, COL_Y) | |-------+-------+------------+--------------------+--------------------+---------------------------| | 1 | NULL | 4 | 0 | 1 | 1 | | 2 | NULL | 24 | 0 | 1 | 1 | | NULL | NULL | 28 | 1 | 1 | 3 | | NULL | 2 | 18 | 1 | 0 | 2 | | NULL | 1 | 10 | 1 | 0 | 2 | +-------+-------+------------+--------------------+--------------------+---------------------------+ 

Copy