title: SELECT * FROM table WHERE column = ??? in PHP with unknown number of values for?
body: <p>I'm trying to show some stuff from my database. There's this column called Genre which can be one out of five different values. Now I want to show only the data for the genres the user has selected by checking checkboxes. The user can choose more than one genre. I know how to show one, two or three genres by using WHERE... AND... but I don't know how many genres the user will select! This is what I use to show data when a checkbox 'actie' is checked:</p>
  
  <pre><code>if (isset($_GET["actie"]))
      {
      $stmt = $db-&gt;prepare("SELECT ProductID,Afbeelding,Product,Prijs,Beschrijving FROM Producten WHERE Genre='Actie' order by Product ASC");
      }
  </code></pre>
  
  <p>How can I do this for multiple checkboxes so that it shows all data for when for instance 'actie' and 'sports' are checked? I'm confused since I don't know how many checkboxes a user will select, none, one, two, three, four or five.
  Thanks in advance for any help!</p>