title: Group By Date With Empty Groups
body: <p>I have a loginAudit table and I am trying to get a count for all logins for each day.  What I'd like to do is have days where there are no logins return their day and a login count of 0.  Currently no row is returned for days with no logins. </p>
  
  <p>Could be this isn't possible and have to fill in empty groups in the app after query results returned?</p>
  
  <pre><code>  SELECT DATEADD(day, DATEDIFF(day,0,LoginAudit.LoginDateTime), 0) as LoginDate,  
           COUNT(DISTINCT LoginAudit.LoginAuditID) AS Logins  
      FROM LoginAudit 
  GROUP BY DATEADD(day, DATEDIFF(day,0,LoginAudit.LoginDateTime), 0)
  ORDER BY 1  
  </code></pre>