UNION

description

Syntax

AGGREGATE_FUNCTION_UNION(agg_state) Aggregate multiple aggregation intermediate results into one. The type of the result is agg_state, and the function signature is consistent with the input parameter.

example

mysql [test]>select avg_merge(t) from (select avg_union(avg_state(1)) as t from d_table group by k1)p;
+----------------+
| avg_merge(`t`) |
+----------------+
|              1 |
+----------------+

keywords

AGG_STATE, UNION