本文介绍了你能定义“字面"吗?SQL中的表?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
是否有任何 SQL 子查询语法可以让您从字面上定义一个临时表?
Is there any SQL subquery syntax that lets you define, literally, a temporary table?
例如，类似
SELECT
MAX(count) AS max,
COUNT(*) AS count
FROM
(
(1 AS id, 7 AS count),
(2, 6),
(3, 13),
(4, 12),
(5, 9)
) AS mytable
INNER JOIN someothertable ON someothertable.id=mytable.id
这样可以省去两到三个查询:创建临时表，将数据放入其中，然后在连接中使用它.
This would save having to do two or three queries: creating temporary table, putting data in it, then using it in a join.
我正在使用 MySQL，但对其他可以做类似事情的数据库感兴趣.
I am using MySQL but would be interested in other databases that could do something like that.
推荐答案
我想你可以用几个 SELECTs 结合 UNIONs 来做一个子查询.
I suppose you could do a subquery with several SELECTs combined with UNIONs.
SELECT a, b, c, d
FROM (
SELECT 1 AS a, 2 AS b, 3 AS c, 4 AS d
UNION ALL
SELECT 5 , 6, 7, 8
) AS temp;
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