On 2/17/07, Rick Schumeyer <rschumeyer@xxxxxxxx> wrote:
This may be bad design on my part, but...
Not at all. Very common scenario
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?
I tried a bunch of cleverness where I checked for existence and updated if required, etc but came back to just zapping them all and inserting. As long as it's done in a transaction and there are not too many, it's fine. It doesn't eat any more space and eats less cycles than doing it the hard way.
Thanks for any advice.
You're welcome!
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.
Sorry about that. Nuff said 8^/ - Ian
