has many ( THROUGH ) confusion

rubyonrails-talk
1

Maybe this is normal operation, but this doesn't seem right to me.

I have models:

- account -- has many listshares -- has many lists ( through listshares )

- list -- has many listshares -- has many accounts ( through listshares )

- listshare --belongs to account --belongs to list

I would have expected that if I perform the action list.destroy, then any records in listshares with the associated list_id would be deleted too.. but they are not.

If they should be, my model is wrong somewhere. If not, I can stop pondering, and code the listshares tidyup manually.

Thanks

Keith

2

You need another declaration in your listshares setup:

has_many :listshares, :dependent => :destroy

In the has many through join model, Listshare is a model in its own right and we'll only be destroyed if you specify so in the relationship.

Hope that helps,

Steve

3

Do you mean that the LIST model should contain

has_many :listshares, :dependent => :destroy ? ( You said listshare)

When I put that in the LIST model, it does remove listshare records if a list is deleted, but now I'm confused about something else of course!

I don't always want to delete a list.. sometimes I want to just remove the relationship between a list and an account - in sql terms to delete from listhshare where account_id = x and list_id = y.

I can't work out how to do that ( apart from using sql )

Thanks in advance

Keith