Foreign keys

Rails
1

Hello,

I’m working on a legacy Rails project (they do exist already!) and I
have
some questions regarding foreign keys.
Could someone point me to references on Rails and foreign keys? They
don’t
seem to be used or encouraged, but I don’t understand why.
Can they be used and set up with migrations? (I know that can pose
problems
with the order of insertion but that can be solved in my case)
How does Rails react when foreign keys give errors?

Thanks for your help,
Bart

2

On 8/29/06, Bart B. [email protected] wrote:

I’m working on a legacy Rails project (they do exist already!) and I have
some questions regarding foreign keys.
Could someone point me to references on Rails and foreign keys? They don’t
seem to be used or encouraged, but I don’t understand why.
Can they be used and set up with migrations? (I know that can pose
problems
with the order of insertion but that can be solved in my case)
How does Rails react when foreign keys give errors?

Many of us are using foreign key constraints in new apps as well.

You can execute the code to manually add/drop them in your migrations or
use
one of the fk migrations plugins.

When you violate a constraint, an ActiveRecord::StatementInvalid
exception
is raised.

jeremy

3

I use
http://www.agilewebdevelopment.com/plugins/foreign_key_schema_dumperall
the time. It allows you to write the fkeys right into your
migrations.

Foreign keys can cause testing headaches, but googling ‘rails foreign
key
testing’ or something similar brings up a lot of good info.