From ac02c190a50370500c72527e30a1da5e0d2da82c Mon Sep 17 00:00:00 2001 From: Ilya Vorontsov Date: Mon, 12 Aug 2013 16:57:29 +0400 Subject: Added comment to a guide about necessity of `:dependent` option for associations with NOT NULL constraint --- guides/source/association_basics.md | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'guides/source') diff --git a/guides/source/association_basics.md b/guides/source/association_basics.md index 9b80a65a44..e133e71d42 100644 --- a/guides/source/association_basics.md +++ b/guides/source/association_basics.md @@ -1137,6 +1137,12 @@ Controls what happens to the associated object when its owner is destroyed: * `:restrict_with_exception` causes an exception to be raised if there is an associated record * `:restrict_with_error` causes an error to be added to the owner if there is an associated object +It's necessary not to set or leave `:nullify` option for those associations +that have `NOT NULL` database constraints. If you don't set `dependent` to +destroy such associations you won't be able to change the associated object +because initial associated object foreign key will be set to unallowed `NULL` +value. + ##### `:foreign_key` By convention, Rails assumes that the column used to hold the foreign key on the other model is the name of this model with the suffix `_id` added. The `:foreign_key` option lets you set the name of the foreign key directly: -- cgit v1.2.3