Hi, I'm somewhat new to SQL so I need a bit of help with this problem. So I have 2 tables: "selection" and "master", both have two columns in each: "user_id" and "date". The "selection" contains one row for each "user_id" and depicts _one_ "date" value for each user. The "master" contains all "date" changes for each "user_id". I.e., there are many dates for each "user_id". It is a history of previous occurrences. Now, I want to add a 3rd column to the "selection" table that is the "date" value from one step back for each "user_id". I.e., if the "master" contains: User1 20010101 User1 20000101 User1 19990101 User1 19970101 for User1, and the "selection" is User1 19990101 I want this to become: User1 20000101 19990101 How do I do this? A simple join wont do it since it is dependent on what value "date" is for each user.. Moreover, I know for a fact that the "date" in "selection" is the second largest value -> I want to add the 3rd largest value from "master" for each user. BR, Jay -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
