[katello-devel] Beware of :id => false in our migrations unless HABTM

[Ohad Levy]

----- Original Message -----

| Hi all,

| Today I've hit and interesting bug in Rails that showed up in our
| project [1].

Is that really a bug? if the many to many relationship is not HABTM
but via a model, then you need a separate ID for it,.. i.e. when
migrating from HABTM to has_may :though, you need to add an ID
column.

Ohad
| How to reproduce (katello-0.1.150-1):

| 1. create a table without primary id (:id => false in our migration)
| (system_tasks in our case)
| 2. create a model for that table (SystemTask)
| 3. use has_many to that model (in System has_many system_tasks)
| 4. create a record in SystemTask
| 5. try to destroy the assigned record (System)
| 6. enjoy NoMethodError: undefined method `eq' for nil:NilClass and
| really long stack trace.

| How to avoid:

| Besides previous hint not to use HABTM there is another rule of
| thumb:

| Don't use :id => false in migrations

| [1] -
| http://stackoverflow.com/questions/5085258/cant-destroy-record-in-many-to-many-relationship

| -- Ivan

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