On Thu, 14 Jun 2007, Lza wrote:
When I run a query on the policy table for a certain period, I also need to be able to pull the correct related rows (i.e. the information that would have been in the table at that time) from the tables linked to it.
Check out "Developing Time-Oriented Database Applications in SQL" by Richard Snodgras; it's an entire book devoted to this and related topics. It's out of print and hard to get, but you can download a free PDF copy from the author at http://www.cs.arizona.edu/people/rts/publications.html
Much of the text shows how to simulate types and operations that now are built-in to PostgreSQL, like the interval type, so it's not quite as intimidating a read as it seems at first; there's a lot of code for older databases that you can completely ignore.
-- * Greg Smith gsmith@xxxxxxxxxxxxx http://www.gregsmith.com Baltimore, MD
