Michael Avila wrote:
> I have a table which keeps track of the status of members. In the table is
>
>
> member_id int(8)
> status_code char(1)
> status_date date
>
> KEY member_id (member_id,status_code,status_date)
>
>
> Each member can have multiple records because a record is added each time
> the status changes but the old record is kept for history.
>
> What I want to do is find the latest status for each member.
Michael Fuhr has already described on solution, but if you can alter the
table definition then there might be a neater solution.
Replace "status_date" with "status_expires" and make it a "timestamp
with time zone". Set the expiry to 'infinity' for the current record and you then have a simple select to find the
mostrecent.
If you regularly want to find which record was active on a particular
time you'll want two columns: valid_from and valid_to. This makes it
much easier to find a row for a specific date.
-- Richard Huxton Archonet Ltd
