screen_name screen_state replies interactions alerts
sjerd       0            20      20           0

SELECT u.screen_name, u.screen_state, count(r.id) AS replies,
   count(i.id) AS interactions,count(a.alerts) AS alerts FROM users u
   LEFT JOIN reply r ON u.id = r.user
   LEFT JOIN interactions i ON u.id = i.user_id
   LEFT JOIN alerts a ON u.id = a.user_id WHERE u.id ='2'
   GROUP BY u.id, u.screen_state