How do I compare two rows within the same table?

Figured it out.. Much faster than a join. :)


SELECT CustomerId,
      CAST(Session_date AS CHAR(11)) AS 'SessDate',
      CAST(NextDate AS CHAR(11)) AS NextDate,
      DATEDIFF(DAY, Session_date, NextDate)
FROM (
      SELECT DISTINCT PT.CustomerId, PT.Session_Date,
            (SELECT MIN(Session_Date)
                  FROM Personal_Training1 AS PTMin
                  WHERE PTMin.Session_Date > PT.Session_Date AND PTMIN.CustomerId = PT.CustomerId) AS 'NextDate'
      FROM Personal_Training1 AS PT
      WHERE CustomerId = 31790
) AS PTCheck
ORDER BY Session_date

Thanks for the help.  :)

Glad I could be of any help ... but your solution is a self join as well :-)