mysql - 如何从联合结果中进行选择？

Question

我有一个这样的 MySQL 脚本：

SELECT ... FROM ... WHERE ...
UNION ALL
SELECT ... FROM ... WHERE ...

现在如何从联合结果中再次选择？

这不起作用：

SELECT * FROM (
    SELECT ... FROM ... WHERE ...
    UNION ALL
    SELECT ... FROM ... WHERE ...
);

Answer 1

您需要为内部查询设置一个别名：

SELECT * FROM (
    SELECT ... FROM ... WHERE ...
    UNION ALL
    SELECT ... FROM ... WHERE ...
) as something;

Answer 2

我想你在问这个：

   SELECT * FROM (
      SELECT ... FROM ... WHERE ...
      UNION ALL
      SELECT ... FROM ... WHERE ...
    )
    WHERE ...