I'm not sure I understand completely, but here's one idea. in the backend, when the user submits their changes: 1) Pull the current state of AccountEmployeeRelation for the account you're working on 2) Compare the current state to what the user posted, and determine what needs to be added and deleted (I use array_diff in php for this) and obviously anything else should get updated. 3) commit This is nice because even if there's relations, if the user makes 3 changes, the database only makes 3 changes, instead of reloading the entire list. If you're worried about concurrent users changing the same accounts, you'll want to lock the account prior to step 1. something like "Select * from Accounts where AccountID=$1 for update" should do nicely. -----Original Message----- From: pgsql-general-owner@xxxxxxxxxxxxxx [mailto:pgsql-general-owner@xxxxxxxxxxxxxx] On Behalf Of Rick Schumeyer Sent: Friday, February 16, 2007 11:31 PM To: pgsql-general@xxxxxxxxxxxxxx Subject: [GENERAL] How would you handle updating an item and related stuff all at once? This may be bad design on my part, but... I have three tables of interest...Account, Employee, and AccountEmployeeRelation. There is a many-to-many relationship between accounts and employees. The join table also contains a column indicating what role the employee plays on this account. My interface is a web app (I'm trying out Ruby on Rails). On the "edit account" screen I want to edit account attributes AND be able to add/delete employees in one form. The gui part seems to work. BUT, when I update I'm not sure how to handle updating the AccountEmployeeRelation table. During the update, relations may have been added or deleted, and existing relations may have been changed. It seems to me the easiest thing to do is delete all the relations for the account and create all new ones with the data submitted from the form. This seems wasteful, but the alternative would be a pain. Or is this really the best way? Thanks for any advice. Completely off topic, (but not worth a separate post) I have been forced to use a little bit of mysql lately...did you know that if you use transaction and foreign key syntax with myisam tables, it does not complain...it just silently ignores your requests for transactions and foreign key checks. Yikes! I had incorrectly assumed I would get an error message indicating that transactions are not supported. Oh well. ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
