基于第二个表字段值的MySQL海量表更新

Question

I have 2 tables, one for user_data and one for user_stats. Im trying to update a field in user_data for all users to a single value ("active") based on the last login field of the user_stats table.

Im trying to avoid a loop since all corresponding fields will just be updated to "active".

Heres basically what Im trying to do: UPDATE user_data SET status = 'active' WHERE user_stats.login <= '$last_login'

Answer 1

Something like the following join should work:

UPDATE user_data, user_stats
SET user_data.status='active'
WHERE user_stats.user_id=user_data.user_id
AND user_stats.last_login <= '$lastlogin'

You may need to change the fields used to join the tables in the update query to suit your tables.

Answer 2

You'll have to nest your query then:

UPDATE user_data SET status = 'active' WHERE user_id IN (SELECT id FROM user_stats WHERE login <= '$last_login')

Overall I'd recommend considering a whole different architecture