title: Count rows in mysql database where timestamp within X interval
body: <p>I am trying to count the rows in a table in my database that were inserted within X hours or X days.  I have tried repeatedly but I keep getting empty set responses.</p>
  
  <p>The start_stamp column in my table is formatted like this: 2013-08-07 18:18:37</p>
  
  <p>I have tried many variations on:
  select * from mytable where start_stamp = now() interval -1 day;</p>
  
  <p>But all to no avail.  Can someone tell me what I am doing wrong?</p>