There is a way, it just isn't part of Rails:
Database constraints. 

I've found that they help fortify my app, especially as there are sometimes 
times when data cleanup thru active record might take 100x more than straight 
SQL.

Sent from my iPhone

On Oct 29, 2011, at 5:40 AM, Michael Q <[email protected]> wrote:

> What is the most DRY way to prevent deletion of a parent if children exist?
> 
> I assume it would be a 
> before_destroy :check_that_no_child_exists
> 
> But an object might have several different types of children and we would 
> ideally want to iterate through all the has_many's with just one command.
> 
> Is there an elegant way of doing this, and returning a helpful error message 
> indicating which type of child exists?
> 
> I'm amazed that Rails still doesn't seem to have a default facility for this 
> as its a very basic requirement.
> 
> Thanks,
> Michael
> -- 
> You received this message because you are subscribed to the Google Groups 
> "Hobo Users" group.
> To view this discussion on the web visit 
> https://groups.google.com/d/msg/hobousers/-/0Awm6SDGCM8J.
> To post to this group, send email to [email protected].
> To unsubscribe from this group, send email to 
> [email protected].
> For more options, visit this group at 
> http://groups.google.com/group/hobousers?hl=en.

-- 
You received this message because you are subscribed to the Google Groups "Hobo 
Users" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/hobousers?hl=en.

Reply via email to