It is necessary to display the number of articles that have read the user's referrals. There are three tables: users, referals(id_user,id_referals(пользователь который пригласил в систему)), history(id_user,id_articles(статья которая прочитана)) .

My request is not true:

 SELECT COUNT( DISTINCT(history.id_articles)), users.login FROM referals,users,history WHERE referals.id_referals = 1 AND users.id = referals.id_user

The user has not read any articles, but displays 3.

  • one
    Where is history.id_user = users.id in WHERE? - user6550

1 answer 1

 users (id, name) referals(id_user,id_referals) history(id_user,id_articles) SELECT referals.id_referals, COUNT(history.id_articles) FROM referals, history WHERE referals.id_referals = 1 AND history.id_user = referals.id_user GROUP BY referals.id_referals

something like that?