title: How to substract from the resut of two selects in mysql
body: <p>I want to substract two numbers, one is the contents of a field, the other is the sum of a query result, how can I do it? this shows what I want, but obviously does not work, how to do it?</p>
  
  <pre><code>SELECT monto FROM programaPago WHERE id=2
   **MINUS**
  SELECT SUM( caja.monto ) FROM caja  WHERE caja.programaPago_id =2
  </code></pre>