title: mysql fetch record with valid date not 0000-00-00 00:00:00
body: <p>i am trying to get all valid timestamp records using below query </p>
  
  <pre><code>SELECT * FROM table where mytimestamp IS NOT NULL
  </code></pre>
  
  <p>my query outputs records with value "0000-00-00 00:00:00"</p>
  
  <p>that id do not want to occurs , what query should be firect in that case</p>