title: SQL Query compare data in different rows
body: <p>I had this question at a job interview yesterday and although it seemed pretty straight fwd I couldn't figure it out and it's kept me awake all night thinking about it.</p>
  
  <p>The system records data about a scrabble league there is a members table, a games table and a joining member_games table.</p>
  
  <pre><code>members: member_id, name : pk(member_id)
  member_games: game_id, member_id, score : pk(game_id, member_id)
  games: game_id, location, date : pk(game_id)
  
  members
  1, mick
  2, keith
  3, charlie
  
  member_games
  1, 1, 50
  1, 2, 60
  2, 1, 45
  2, 3, 105
  3, 1, 30
  3, 3, 120
  
  game
  1, london, 2012-12-01
  2, richmond, 2012-12-02
  3, leeds, 2012-12-03
  </code></pre>
  
  <p>How do you formulate an SQL query to find out the number of wins for the <code>member_id</code> = 1?</p>