title: Can Doctrine QueryBuilder andWhere() used without where()?
body: <p>In Doctrine, when building a query with QueryBuilder, does the first <code>where</code>clause have to be defined with <code>$qb-&gt;where()</code>or can I use <code>$qb-&gt;andWhere()</code> directly. For example, is this valid:</p>
  
  <pre><code>$qb-&gt;select('Mystuff\Entity\User','u');
  $qb-&gt;andWhere('usertype = :usertype');
  $qb-&gt;andWhere('usercategory = :usercategory');
  </code></pre>
  
  <p>Or, as a more relevant example:</p>
  
  <pre><code>$filter = array('usertype'=&gt;'basic','usercategory'=&gt;'business');
  $qb-&gt;select('Mystuff\Entity\User','u');
  foreach ($filter as $fkey =&gt; $fval) {
     $qb-&gt;andWhere($fkey.' = :'.$fval);
  }
  </code></pre>