title: Determine if CodeIgniter active record have set a WHERE-clause
body: <p>Sooo! Well, the title should say most of it.
  Are there any way to check if <code>$this-&gt;db-where('stuff', $data)</code> has been set previously?</p>
  
  <p>I could go out and make a bunch of testing of my own code (flags ect...), but I would like to know if anyone has knowledge of some fast and easy way to do it!</p>
  
  <p>Thanks in advance!</p>
  
  <p>[EDIT - 24-Apr-14]
  It's my own code. I have to variable that can be <code>null</code>, <code>String</code> or an <code>array</code>. They are <code>$categories</code> and <code>$budget</code>. So if budget is set to <code>100$</code> and category is set to <code>stuff</code> then I will need to use <code>db-&gt;or_where</code>, but if only one of them is set, I need only to use <code>db-&gt;where</code>. In this case it is quite simple just to check if first is set, but what if more values are used? I hope you get the point :)</p>