Getting “Unknown primary key for table” while the

Question

I've been debugging this strange problem of Rails giving me "Unknown primary key for table...", even when the table's ID is there.

I've copied the database from one heroku app to another, on the original databse there is no problem and the new one gives me a db error.

This is the error:

ProductsController# (ActionView::Template::Error) "Unknown primary key for table collections in model Collection."

/app/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.13/lib/active_record/reflection.rb:366:in `primary_key'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.13/lib/active_record/reflection.rb:480:in `association_primary_key'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.13/lib/active_record/associations/association_scope.rb:58:in `block in add_constraints'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.13/lib/active_record/associations/association_scope.rb:39:in `each'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.13/lib/active_record/associations/association_scope.rb:39:in `each_with_index'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.13/lib/active_record/associations/association_scope.rb:39:in `add_constraints'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.13/lib/active_record/associations/association_scope.rb:31:in `scope'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.13/lib/active_record/associations/association.rb:98:in `association_scope'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.13/lib/active_record/associations/association.rb:87:in `scoped'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.13/lib/active_record/associations/collection_association.rb:573:in `first_or_last'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.13/lib/active_record/associations/collection_association.rb:105:in `last'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.13/lib/active_record/associations/collection_proxy.rb:46:in `last'
/app/app/helpers/likes_helper.rb:62:in `significant_liker'

The line that causes it:

product.collections.last.try :user

and the table:

d8apjspa441pad=> \d collections
                                     Table "public.collections"
     Column     |          Type          |                        Modifiers                         
----------------+------------------------+----------------------------------------------------------
 id             | integer                | not null default nextval('collections_id_seq'::regclass)
 name           | character varying(255) | 
 user_id        | integer                | 
 permalink      | character varying(255) | 
 category_id    | integer                | 
 products_count | integer                | 
 is_featured    | boolean                | 
Indexes:
    "index_lists_on_user_id_and_permalink" UNIQUE, btree (user_id, permalink)

Any idea why this might happen?

Thanks!

Answer 1

I was having a similar problem and this was the only page I could find. So just in case it will be of help to anyone else...

I started suddenly getting missing primary key messages on a couple tables. I'm guessing, but not sure, that this started happening after pushing data (pg_dump local, heroku pg:restore)

The primary keys in question were both on tables that had been renamed so that the pkey name did not match the table name--but on the other hand lots of other renamed tables were in the same boat and did not have problems.

Anyway, at one point in my flailing around I tried uploading another dump file and I noticed some complaints on the offending indices. First it would try to delete them and complain that it couldn't because they did not exist. Later it would try to create them and complain that it couldn't because they already existed.

Very annoying considering that pkey info doesn't show up in schema.rb and is supposed to 'just work', right?

Anyway, what worked for me (and thus the reason I'm posting) is to do a heroku pg:reset and then load the dump again. Side note, I got 'internal server error' the first two times I tried heroku pg:reset. But later I tried again and it worked.

Answer 2

restarting the heroku server worked for me. Maybe it was the spring-preloader which was recognizing the empty db-schema, during the db-restorement

Answer 3

If you're trying to troubleshoot this issue make sure you check your logs carefully. I noticed an earlier error related to a js asset that wasn't being precompiled. This got lost in the stack of rendering messages.

Once I fixed the asset precompilation issue, the 'Unknown primary key for table' error was no longer thrown.

This was 100% definitely the only thing I changed.