ActiveRecord doesn't find posgresql sequences

Rails
1

Hello all,

I used to develop using Rais + Mysql, now I need to switch to
Postgresql.

I can’t figure out why ActiveRecord cannot find the sequence needed for
incrementing the id of my table.

The name of the table is users, the name of the sequence is
users_id_seq: (is this the orrect name? )

    CREATE TABLE users (
        id int,
        first_name varchar(50),
        constraint users_pkey PRIMARY KEY (id)
    );

    CREATE SEQUENCE users_id_seq
        START WITH 1
        INCREMENT BY 1
        NO MAXVALUE
        NO MINVALUE
        CACHE 1;

Well, saving a new records fails:

ruby script\runner “a = User.new(:first_name => ‘Jack’) ; a.save”
c:/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6/lib/commands/runner.rb:27:
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/connection_adapters/abstract_adapter.rb:120:in
`log’:
RuntimeError: ERROR C23502 Mnull value in column “id” violates
not-null constraint FexecMain.c L1806 RExecConstraints:
INSERT INTO users (“first_name”) VALUES(‘Jack’)
(ActiveRecord::StatementInvalid)

Ok, well, then I set the sequence manually:

    class User < ActiveRecord::Base
      set_sequence_name "users_id_seq"
    end

It has no effect! It’s rather annoying.

What am I missing here?

Best regards,
Yuri

P.S.
I am using
postgres-pr (0.4.0)
rails (1.1.6)
activerecord (1.14.4)
postgresql 8.1

2

Or am I supposed to use

id int default nextval('users_id_seq')  ?

Am I right?

I thought Postgres adaptor will handle it by itself, but I didn’t find
in in the source code.

Best regards
Yuri

3

On 9/19/06, Yuri L. [email protected] wrote:

Or am I supposed to use

id int default nextval('users_id_seq')  ?

Am I right?

I thought Postgres adaptor will handle it by itself, but I didn’t find
in in the source code.

id must have a default nextval. The postgres adapter will deduce it if
you
provide it.

Defining your tables with
id serial primary key
is the typical idiom.

jeremy

4

Hi,

Jeremy K. wrote:

id must have a default nextval. The postgres adapter will deduce it if you
provide it.

Defining your tables with
id serial primary key
is the typical idiom.

Well, I read the source code of ActiveRecord::Base and the postgres-pr
adaptor and found out that the deduction you are referring to works
only for figuring out the id of the record just created:

  def insert(sql, name = nil, pk = nil, id_value = nil,

sequence_name = nil) #:nodoc:
execute(sql, name)
table = sql.split(" ", 4)[2]
id_value || last_insert_id(table, sequence_name ||
default_sequence_name(table, pk))
end

Well, that’s ok, I’m fine with the rdbms taking care of incrementing
the pk, I just had false expectations about Active Record, because in
some O/R Mappers I used in the past (OJB) you can configure it to take
care of the PKs.

Well, problem’s solved, no, there’s no problem, I’m pretty happy with
ActiveRecord.

Yuri