mysql - Update table from other table -


i have table stores user-submitted posts in posts table. users can "like these posts. likes stored in likes table, 1 row per like, columns id, user, , postid.

i've added column likes posts table. how can update likes column in posts table every post, reflect amount of likes post in thelikestable?

tia!

a version subquery

update posts p    set likes = (select count(*) likes postid = p.postid)

sqlfiddle


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