title: in date_sub function while using a interval can we use an interval of month and day combined?
body: <p>If I need to select database for the past month is this the correct way?</p>
  
  <pre><code>$month1=mysql_query("select * from users where date_sub(concat(curdate(), ' 00:00:00'), interval 1 month day(curdate()) day) &lt; start and start &lt; date_sub(concat(curdate(), ' 00:00:00'), interval day(curdate()) day)");
  </code></pre>
  
  <p>Is this field correct in particular: <code>date_sub(concat(curdate(), ' 00:00:00'), interval 1 month day(curdate()) day)</code></p>
  
  <p>Is there any best short alternative to simply select a table of <strong>JUST the previous month</strong> from the DB?</p>