title: Compare two columns in same table
body: <p>Guys how can I make this query work</p>
  
  <pre><code>SELECT SUM(iznos_fakture) as ukupno 
  FROM fakture_placanja 
  WHERE iznos_placanja &lt;&gt; iznos_fakture 
  AND MONTH(datum_dospijeca) = '12' 
  </code></pre>
  
  <p>I need to find where iznos_placanja (decimal 10,2) is different from iznos_fakture (Decimal 10,2). They are two columns in same table?</p>
  
  <p>I want to find all invoices (iznos_fakture) which are due in December (MONTH(datum_dospijeca)) and have not been payed yet (iznos_placanja).</p>
  
  <p>Nulls are allowed.</p>
  
  <p>Any ideas?</p>