mysql - 如何在一个查询中执行多个不同的计数聚合

Question

我正在执行查询，必须选择 count(*) 输出并将结果插入到另一个表中，如下所示:

INSERT INTO db1.table1 (stopped) SELECT count(*) 
FROM db2.table2 WHERE condition=2;

但是，我需要这个查询根据不同的条件对输出进行计数。如何将所有此类查询合并为一个查询？

INSERT INTO db1.table1 (active) SELECT count(*) 
FROM db2.table2 WHERE condition=1;
INSERT INTO db1.table1 (susp) SELECT count(*) 
FROM db2.table2 WHERE condition=2 and option=4;

Answer 1

您可以尝试使用union all

SELECT count(*)  as cnt FROM db2.table2 WHERE condition=2
union all
SELECT count(*) FROM db2.table2 WHERE condition=1
union all 
SELECT count(*) FROM db2.table2 WHERE condition=2 and option=4