title: How to drop function if it already exist in mysql
body: <p>I have defined custom function in mysql (using Rails 3 btw), beginning of the definition was like that</p>
  
  <pre><code>CREATE FUNCTION SOURCE_NAME(source INT(10))
  </code></pre>
  
  <p>This function works fine but now i need to drop it with mysql <code>drop function</code> statement.</p>
  
  <p>This is the list of what i've tried already, none works, they only raise exceptions:</p>
  
  <pre><code>DROP FUNCTION IF EXISTS SOURCE_NAME;
  DROP FUNCTION IF EXISTS SOURCE_NAME
  DROP FUNCTION IF EXISTS SOURCE_NAME();
  DROP FUNCTION IF EXISTS SOURCE_NAME()
  DROP FUNCTION IF EXISTS 'SOURCE_NAME'
  DROP FUNCTION IF EXISTS 'SOURCE_NAME';
  </code></pre>
  
  <p>and i have no idea what to do next, every example i find online looks different...</p>