title: insert query with a subquery
body: <p>i tried to use the following query to insert data in a table and got an error</p>
  
  <pre><code>insert into filmo_person_song (person_id, song_id, role_id)
  select person_id
  from filmo_person_song fps, filmo_song fs, filmo_role fr
  where fps.song_id = fs.song_id
    and fps.role_id = fr.role_id
    and fps.person_id = 43629;
  </code></pre>
  
  <p>ERROR 1136 (21S01): Column count doesn't match value count at row 1</p>
  
  <p>i have specified the fields exactly..</p>