# PostgreSQL primary (sequence) key issue (Ruby/Rails)

**URL:** <https://www.ruby-forum.com/t/postgresql-primary-sequence-key-issue-ruby-rails/87334>\
**Category:** Rails\
**Created:** [March 1, 2007, 8:20pm UTC](https://www.ruby-forum.com/t/postgresql-primary-sequence-key-issue-ruby-rails/87334 "2007-03-01T20:20:05Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![akm](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/57b2e6/32.png) [@akm](https://www.ruby-forum.com/u/akm)\
**Post date:** [March 1, 2007, 8:20pm UTC](https://www.ruby-forum.com/t/postgresql-primary-sequence-key-issue-ruby-rails/87334/1 "2007-03-01T20:20:05Z")

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Hi Guys,  
I’m completely stumped with this one!

I’ve included ActiveRecord::Base.set\_sequence\_name in my environment.rb,  
and  
in my user.rb I’ve placed the following code:

class Usertbl \< ActiveRecord::Base  
set\_primary\_key “user\_id”  
set\_sequence\_name “seq\_user\_mytable”  
validates\_uniqueness\_of :userpassword, :username, :scope =\> :user\_id  
end

From [http://localhost:3000/usertbl/new](http://localhost:3000/usertbl/new) I then attempt to enter a new a  
record and receive the following error message:

RuntimeError: ERROR C23502 Mnull value in column “user\_id” violates  
not-null constraint

FexecMain.c L1795 RExecConstraints: INSERT INTO usertbl

Oh my head hurts!!

–  
Regards

Andrew