Question

i have one table, which contains that fields

mid , email
  1 , 'user_a@...'  
  2 , 'user_b@...' 
  3 , 'user_c@...' 

and then another table with the following fields / values

tid, name  
  1, t_a
  2, t_b 
  3, t_c 

and other table

tid, mid
  1, 1
  1, 2
  1, 3
  2, 2
  2, 3
  3, 1
  3, 2

How can i get all users that have ‘t_a’ and ‘t_b’ .. i need to return

user_a,
user_c

Because user_b does not contains t_a

Answer 1

SELECT e.email
    FROM emails e
        INNER JOIN email_tags et
            ON e.mid = et.mid
        INNER JOIN tags t
            ON et.tid = t.tid
    WHERE t.name IN ('t_a', 't_b')
    GROUP BY e.email
    HAVING COUNT(DISTINCT t.name) = 2