title: PostgreSQL - Creating a trigger: function does not exist
body: <p>I'm working on a script for school right now and I've encountered a weird error that I can't fix.
  So I've got a playlist, tracks and a playlistInput table.
  My task is to create a trigger that if I add/delete a track to my playlist, the amountOfTracks variable should be increased/decreased.</p>
  
  <p>So now to the weird error:
  I've made a function "playlistInputAdd" which already works when doing "select playlistInputAdd(1,1)".
  The thing is that if I create my trigger, it says that this function doesn't exist. I've seen that someone asked the same question but he didn't add the parameters and I actually did.</p>
  
  <p>The playlistInputAdd function:</p>
  
  <pre><code>CREATE FUNCTION playlistInputAdd(ID int, Amount int)
  RETURNS VOID
  AS $$
  BEGIN
      UPDATE playlist
      SET amountOfTracks = amountOfTracks + Amount
      WHERE playListID = ID;
  END;
  $$ LANGUAGE plpgsql;
  </code></pre>
  
  <p>The playlistInputAdd_trigger trigger:</p>
  
  <pre><code>CREATE TRIGGER playlistInputAdd_trigger 
  AFTER INSERT
  ON playlistInput 
  FOR EACH ROW 
  EXECUTE PROCEDURE playlistInputAdd(playlistID, 1);
  </code></pre>
  
  <p>The playlistInputDelete_trigger trigger:</p>
  
  <pre><code>CREATE TRIGGER playlistInputDelete_trigger 
  AFTER INSERT
  ON playlistInput 
  FOR EACH ROW 
  EXECUTE PROCEDURE playlistInputAdd(playlistID, 1);
  </code></pre>
  
  <p>The error message:</p>
  
  <pre><code>ERROR: function playlistinputadd() does not exist
  </code></pre>
  
  <p>Thank you, in advance!</p>