mysql - 将“OR”用于多个子查询是否最优？

Question

我对下面的表格有一个缓慢的询问。

SELECT DISTINCT * FROM table e
WHERE e.eid in (select eid from view1)
OR e.eid in (select eid from view1)
OR e.eid in (select eid from view2)
OR e.eid in (select eid from view3)
OR e.eid in (select eid from view4)
OR e.eid in (select eid from view5)

我是MySQL新手，但是有没有更快的方法来进行这个查询呢？

Answer 1

可能会像这样使用UNION：

SELECT DISTINCT * FROM table e
WHERE e.eid IN
(
    SELECT eid FROM view1
    UNION
    SELECT eid FROM view2
    UNION
    SELECT eid FROM view3
    UNION
    SELECT eid FROM view4
    UNION
    SELECT eid FROM view5
)