title: In SQL, how to delete a row from one table if it doesn't have a corresponding row in another table?
body: <p>How can I make:</p>
  
  <p>DELETE FROM foo WHERE id=1 AND <strong>bar not contains id==1</strong></p>
  
  <p>To elaborate, how can I remove a row with <code>id = 1</code>, from table <code>foo</code>, only if there is not a row in table <code>bar</code> with <code>id = 1</code>.</p>