title: How to build this mongodb WHERE query in PHP?
body: <p>I want to build a mongodb query in PHP</p>
  
  <p>like this in SQL:</p>
  
  <pre><code>select * from tbl where a=3 and b=4
  </code></pre>
  
  <p>I know this WHERE statement in PHP should be:</p>
  
  <pre><code>array('$all' =&gt; array('a' =&gt; 3, 'b' =&gt; 4);
  </code></pre>
  
  <p>but how to build a WHERE like this:</p>
  
  <pre><code>select * from tbl where (a=3 or b=4) and c=5
  </code></pre>