您可以为 not in 查询使用多列吗? [英] Can you use multiple columns for a not in query?

问题描述

我最近看到有人将此作为对 SO 查询问题的回答的一部分发布:

I recently saw someone post this as part of an answer to an SO query question:

SELECT DISTINCT a, b, c 
FROM t1 
WHERE (a,b,c) NOT IN 
   ( SELECT DISTINCT a,b,c FROM t2 )

我有点困惑，因为我一直认为NOT IN"不能使用多列(where(a,b,c)"等).这是正确的 SQL 语法吗?MySQL呢?

I'm a bit confused, as I always thought that you can't use multiple columns for "NOT IN" ("where(a,b,c)", etc.). Is this correct SQL syntax? And how about MySQL?

推荐答案

这是一个 SQL 扩展.Oracle、PostgreSQL 和 MySQL 都有.SQL Server 2005 没有它.我不确定其他人.

It's a SQL extension. Oracle, PostgreSQL and MySQL have it. SQL Server 2005 does not have it. I'm not sure about others.

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