UNION

UNION

description

Syntax

AGGREGATE_FUNCTION_UNION(agg_state) 将多个聚合中间结果聚合为一个。 结果的类型为agg_state，函数签名与入参一致。

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