GROUPING

Returns a bit mask indicating which GROUP BY expressions are not included in the current grouping set. Bits are assigned with the rightmost argument corresponding to the least-significant bit; each bit is 0 if the corresponding expression is included in the grouping criteria of the grouping set generating the current result row, and 1 if it is not included.

Syntax

GROUPING ( expr [, expr, ...] )

备注

GROUPING can only be used with GROUPING SETS, ROLLUP, or CUBE, and its arguments must be in the grouping sets list.

Arguments

Grouping sets items.

Return Type

UInt32.

Examples

select a, b, grouping(a), grouping(b), grouping(a,b), grouping(b,a) from t group by grouping sets ((a,b),(a),(b), ()) ;
+------+------+-------------+-------------+----------------+----------------+
| a    | b    | grouping(a) | grouping(b) | grouping(a, b) | grouping(b, a) |
+------+------+-------------+-------------+----------------+----------------+
| NULL | A    |           1 |           0 |              2 |              1 |
| a    | NULL |           0 |           1 |              1 |              2 |
| b    | A    |           0 |           0 |              0 |              0 |
| NULL | NULL |           1 |           1 |              3 |              3 |
| a    | A    |           0 |           0 |              0 |              0 |
| b    | B    |           0 |           0 |              0 |              0 |
| b    | NULL |           0 |           1 |              1 |              2 |
| a    | B    |           0 |           0 |              0 |              0 |
| NULL | B    |           1 |           0 |              2 |              1 |
+------+------+-------------+-------------+----------------+----------------+