title: mySQL JOIN columns and count distinct on one table and get more values on other table
body: <p>I'm doing a db to organize my movies. I have two tables (1 for movies one for actors). Putting it simple and omitting useless fields for this exercise</p>
  
  <pre><code>Table MOVIE: 
      id_movie | name_movie | star1 | star2 | star3 | runtime
  
  Table ACTOR: 
      id_actor | name | sex | image
  </code></pre>
  
  <p>There are movies where the star1 is for example "Morgan Freeman" but on other movies "Morgan Freeman" is in the field star2.</p>
  
  <p>I wanna count <code>DISTINCT</code> values from the <code>UNION</code> of star1, star2, star3 from the table MOVIE and then go get the actor/actress sex and image on the table ACTOR.</p>
  
  <p>Already tried all different kinds of queries but no results so far :( </p>
  
  <p>Can anyone help me on this one?</p>