SQL join on multiple columns in same tables
SqlJoinSql Problem Overview
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;
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 ??
Any help appreciated.
Sql Solutions
Solution 1 - Sql
You need to replace the second ON with AND, like this:
ON a.userid = b.sourceid AND a.listid = b.destinationid;
Solution 2 - Sql
You want to join on condition 1 AND condition 2, so simply use the AND keyword as below
ON a.userid = b.sourceid AND a.listid = b.destinationid;