title: How to filter out nulls in google bigquery
body: <p>I don't seem to find a way in Bigquery to filter out <code>nulls</code> like we do in SQL server database, e.g. <code>WHERE Column1 IS NOT NULL</code>.</p>
  
  <p>Can anyone shed some light on this please?</p>
  
  <p>Thanks.</p>