Changing primary key

rubyonrails-talk
1

I have changed the primary key on a table “statuses” to now be entity_id

In my status model I have:

self.primary_key = 'entity_id'

when I try to render a collection of comments associated with a status like so:

<%= render @comments %>

I get this error:

PG::UndefinedColumn: ERROR: column comments.status_id does not exist LINE 1: SELECT "comments".* FROM "comments" WHERE "comments"."status_id"

I'm assuming when the above call is constructed by rails it is assuming the table statuses has primary key status.id by convention..

so – is it no longer possible to use the render functionality as above? Or have I missed something which I need to make this work?

How can I get rails to use entity_id instead of the now changed status_id?

2

Hi

I have changed the primary key on a table “statuses” to now be entity_id

In my status model I have:

self.primary_key = 'entity_id'

when I try to render a collection of comments associated with a status like so:

<%= render @comments %>

I get this error:

PG::UndefinedColumn: ERROR: column comments.status_id does not exist LINE 1: SELECT "comments".* FROM "comments" WHERE "comments"."status_id"

I'm assuming when the above call is constructed by rails it is assuming the table statuses has primary key status.id by convention..

All it does is taking the model name and suffix it with _id. Specifying :foreign_key option should work.

:foreign_key     Specify the foreign key used for the association. By default this is     guessed to be the name of this class in lower-case and “_id”     suffixed. So a Person class that makes a has_and_belongs_to_many     association to Project will use “person_id” as the default     :foreign_key.

3

Hmmm..

OK, I have put this in place:

class Comment < ApplicationRecord   belongs_to :user   belongs_to :published_entity, foreign_key: "entity_id"

but rails is still trying to use status_id..

(I have a class PublishedEntity which status inherits from)

class Status < PublishedEntity   self.table_name = 'statuses'   self.primary_key = 'entity_id'

maybe this is causing problems?

4

What exactly is @comments?

Fred

5

Hi Fred,

@comments is a collection of comments on a status

Johnny

6

Hi,

7

Thanks Nanaya,

looks like that will do the trick!

Johnny

8

OK, next problem..

When I create a comment (from a form on the status page) the params hash contains a parameter called: status_entity_id What I want is just: entity_id

Processing by CommentsController#create as JS   Parameters: {"utf8"=>"✓", "comment"=>{"content"=>"testing123"}, "commit"=>"Add Comment", "status_entity_id"=>"13"}

I assume rails is prepending the name of the controller to the id? Is there a way to override this?