UNION
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