title: ID from insert with multiple rows
body: <p>Is it safe to assume that the auto increment id from a insert with multiple rows will be incremented by one starting to the <code>mysql_last_insert_id()</code> value? Could there be a concurrent insert (from an other user session) between this multiple insert?</p>
  
  <p>In this example <code>tbl_name</code> has an autoincrement field called <code>id</code>:</p>
  
  <pre><code>INSERT INTO tbl_name (a,b,c) VALUES(1,2,3),(4,5,6),(7,8,9);
  
  $nbAffectedRows = mysql_affected_rows();
  $idFirstRowInserted = mysql_last_insert_id();
  
  $arrayId = array();
  if($nbAffectedRows &amp;gt; 0){
      for($i = 0; $i &amp;lt;= $nbAffectedRows; $i++){
          $arrayId[] = $idFirstRowInserted + $i;
      }
  }
  </code></pre>
  
  <p>Will <code>$arrayId</code> always contain values incremented by one correponding to the 'id' of the rows inserted ?</p>