title: SELECT multiple rows WHERE matching two conditions
body: <p>This would be better to show on my example:</p>
  
  <p>I have table, where are stored users answers from one big form. Each form has 139 questions. These questions are stored in different table, joined when needed with questionID. For each user, there is an ID. I now need to make filters, to show only users matching one or <strong>more</strong> answers on specific questions. </p>
  
  <p>For example, i want users, where question 14 has answer "yes", question 54 is not empty and question 100 is bigger than 10. This is how the table looks:</p>
  
  <pre><code>**userID** | **questionID** | **answer**
  
  1            14               "yes"
  1            54               "something"
  1            100              "9"
  2            14               "no"
  2            54               "north
  2            100              "50"
  3            14               "yes"
  3            54               "test"
  3            100              "12"
  </code></pre>
  
  <p>as result i want only the <strong>userID</strong> 3 returned, because it meets all conditions.</p>
  
  <p>This would be easy to reach with ColdFusion, as it allows query in queried results, but in PHP i haven't found any way. It is important to have chance to add random number of questions, not only three as in this example.</p>