CODEWITHSUNDEEP
mysqlarrayscompare
medk
medk

Reputation: 9529

mysql compare two tables

I have a mysql database that has 2 table. the first table contains the user information, and the second table contains the votes. there is a common field between the two (userid).

but after checking the num rows in each table I found that the first table contains nearly 1000 users more than the second, so there are almost 1000 members whio didn't vote.

I want to query the two tables and get an array containing the userid of the members who didn't vote.

How to?

Thanks.

Upvotes: 0

Views: 506

Answers (1)

Māris Kiseļovs
Māris Kiseļovs

Reputation: 17285

You need to join both tables and filter out which users don't have corresponding record in votes table.

SELECT id FROM members
LEFT JOIN votes ON userid=id
WHERE votes.userid IS NULL

Upvotes: 2

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