title: How to get day of week in SparkSQL?
body: <p>I am trying to select all record recorded at Sunday through SparkSQL.
  I have the following try but in vain.</p>
  
  <pre><code>SELECT * FROM mytable WHERE DATEPART(WEEKDAY, create_time) = 0
  SELECT * FROM mytable WHERE strftime("%w", create_time) = 0
  </code></pre>
  
  <p>How to get day of week in SparkSQL?</p>