Categories:

Aggregate Functions (General)

# GROUPING¶

Describes which of a list of expressions are grouped in a row produced by a GROUP BY query.

Aliases:

GROUPING_ID

## Syntax¶

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


## Usage Notes¶

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

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

## Examples¶

Group by sets:

Create and populate a table with values:

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);


Show the values in the table:

SELECT * FROM aggr2 ORDER BY col_x, col_y, col_z;
+-------+-------+-------+
| COL_X | COL_Y | COL_Z |
|-------+-------+-------|
|     1 |     2 |     1 |
|     1 |     2 |     3 |
|     2 |     1 |    10 |
|     2 |     2 |     3 |
|     2 |     2 |    11 |
+-------+-------+-------+


Output:

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