如何在Rails 2上的级联上删除

Question

I have this DB design:

contracts

• id
• name

allotment

• id
• name
• contract_id

allotments_rooms

• id
• allotment_id
• room_id

• 1 contract has 1 allotment
• 1 allotment has N allotments_rooms

So…

 Contract has_one :allotment, :dependent => :delete_all Allotment belongs_to :contract Allotment has_many :allotments_rooms, :dependent => :delete_all Allotments_Rooms belongs_to :allotment 

So, when I delete a Contract, the Allotment is perfectly removed, but the allotments_rooms are not.

Why?

Thank you!

Answer 1

when you use :dependent => :delete_all , you destroy dependent records without calling their destroy method , so they have no chance to destroy their own associated records. Try :dependent => :delete instead.

i would also recommend using the foreigner gem if you want to set FK constraints at DB level (though i don't know if it works with rails 2)