title: php mysql combine queries
body: <p>If I have 2 mysql_query commands in a single php file, is their a way to combine them?</p>
  
  <p>For example, I have:</p>
  
  <pre><code>$a=mysql_query(SELECT * FROM table1);
  $b=mysql_query(SELECT id FROM table3);
  </code></pre>
  
  <p>but I want to combine them into a single mysql_query, would this be more efficient? would it be faster?</p>