title: Postgresql how to find distinct values and count
body: <p>I have a table with ID, data 1, and few other columns... data 1 has NA as well.</p>
  <p>I need to find a distinct ID, followed by the total count of each ID and the count for each ID whose data has NA. I need to determine how much of NA values are loaded for each ID.</p>
  <p>Thanks
  Sai</p>