同一表中多列的 SQL 连接 [英] SQL join on multiple columns in same tables
本文介绍了同一表中多列的 SQL 连接的处理方法,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
我有 2 个子查询,但是我无法将同一个表中的列连接在一起.我试过了:
I have 2 subqueries, but I'm having trouble joining columns together from the same tables. I tried:
SELECT * FROM
(SELECT userid, listid
FROM user_views_table
WHERE date='2013-05-15' AND view_type='lists') a
JOIN
(SELECT sourceid, destinationid
FROM actions_table
WHERE date='2013-05-15' AND payloadtype='lists_user' AND actiontype='delete') b
ON a.userid = b.sourceid
ON a.listid = b.destinationid;
如果我只是用 ON a.userid = b.sourceid
结束查询,它可以工作,但是我如何也将这些表加入另一列 ON a.listid = b.目的地id
??
If I simply end the query with ON a.userid = b.sourceid
it works, but how can I also join these tables on another column also ON a.listid = b.destinationid
??
感谢任何帮助.
推荐答案
你需要用AND
替换第二个ON
,像这样:
You need to replace the second ON
with AND
, like this:
ON a.userid = b.sourceid AND a.listid = b.destinationid;
这篇关于同一表中多列的 SQL 连接的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文