SQL连接同一表中的多个列 [英] SQL join on multiple columns in same tables

问题描述

我有2个子查询，但是我无法将同一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;

如果我只是简单地以ON a.userid = b.sourceid结束查询，则可以，但是如何将这些表也连接到另一个列上呢?ON a.listid = b.destinationid?

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 ??

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推荐答案

像这样加入:

ON a.userid = b.sourceid AND a.listid = b.destinationid;

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