The table is not empty. I did some playing around with the SQL Statement but got no where. So I added a record status column that will be non-NULL when the status becomes history because a new status is added. Yeah, I cheated to make it easy!! LOL But it now works and that is what counts!
Thanks for the help. Mike > -----Original Message----- > From: Michael Fuhr [mailto:[EMAIL PROTECTED] > Sent: Saturday, December 17, 2005 7:26 PM > To: Michael Avila > Cc: SQL PostgreSQL MailList > Subject: Re: [SQL] Need SQL Help Finding Current Status of members > > > On Fri, Dec 16, 2005 at 07:44:46PM -0500, Michael Avila wrote: > > Just tried it and it returned nothing. > > > > > > Select * from memberstatus A where not exists > > > > (select * from emberstatus B where B.member_id=A.member_id and > > > > B.status_date >A.status_date) > > > > Why the WHERE NOT EXISTS? > > The query selects each row in memberstatus for which no other rows > (WHERE NOT EXISTS) with the same member_id have a later status_date; > in other words, the row(s) with the latest status_date for each > member_id. For example, given > > member_id | status_code | status_date > -----------+-------------+------------- > 1 | a | 2005-12-01 > 1 | b | 2005-12-02 > 1 | c | 2005-12-03 > 2 | x | 2005-12-11 > 2 | y | 2005-12-12 > 2 | z | 2005-12-13 > > the query should return > > member_id | status_code | status_date > -----------+-------------+------------- > 1 | c | 2005-12-03 > 2 | z | 2005-12-13 > > Offhand I can't think of why the query would return nothing unless > the table is empty, but maybe I'm overlooking something or making > unwarranted assumptions about the data. Can you post a sample data > set for which the query returns no rows? > > -- > Michael Fuhr ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
