Rails 3, Postgresql Schemas, and schema.rb

[mgerst...@gmail.com]

Hi All,

Has anyone worked with Rails 3 and Postgresql schemas? I'm working on a multi-tenant Rails3 (beta 4) application where each account will have it's own schema in a postgresql database. What I've done so far (with help from http://www.developerit.com/2010/05/07/creating-a-multi-tenant-application-using-postgresqls-schemas-and-rails), is to create an Account and then call a method that creates a new postgres schema and then load the rails schema.rb into the newly created schema.

The method I call after creation is the following:

  def self.create_new_schema_and_load_rails_schema(schema)
    conn = ActiveRecord::Base.connection
    conn.execute("CREATE SCHEMA #{schema}")  
    conn.execute("SET search_path TO #{schema}")   
    file = "#{Rails.root}/db/schema.rb"
    load(file)
    conn.execute("SET search_path TO #{conn.schema_search_path}")
  end


This fails at 'load(file)'. When I attempt to do something similar in the console:

>Account.create(:name => 'Draper', :domain => 'dondraper.com')
>conn.execute("create schema dondraper")
>conn.execute("SET search_path TO dondraper")
>file = "#{Rails.root}/db/schema.rb"
>load(file)

I get the following error:

-- create_table("accounts", {:force=>true})
ActiveRecord::StatementInvalid: PGError: ERROR:  table "accounts" does not exist
: DROP TABLE "accounts"
    from /usr/local/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/connection_adapters/abstract_adapter.rb:210:in `log'
    from /usr/local/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/connection_adapters/postgresql_adapter.rb:464:in `execute'
    from /usr/local/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/connection_adapters/abstract/schema_statements.rb:192:in `drop_table'
    from /usr/local/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/connection_adapters/abstract/schema_statements.rb:112:in `create_table'
    from /usr/local/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/migration.rb:356:in `send'
    from /usr/local/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/migration.rb:356:in `method_missing'
    from /usr/local/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/migration.rb:332:in `say_with_time'
    from /usr/local/lib/ruby/1.8/benchmark.rb:293:in `measure'
    from /usr/local/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/migration.rb:332:in `say_with_time'
    from /usr/local/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/migration.rb:352:in `method_missing'
    from /home/admin/a2/db/schema.rb:14
    from /usr/local/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/schema.rb:49:in `instance_eval'
    from /usr/local/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/schema.rb:49:in `define'
    from /home/admin/a2/db/schema.rb:12
    from /usr/local/lib/ruby/gems/1.8/gems/activesupport-3.0.0.beta4/lib/active_support/dependencies.rb:208:in `load'
    from /usr/local/lib/ruby/gems/1.8/gems/activesupport-3.0.0.beta4/lib/active_support/dependencies.rb:208:in `load'
    from /usr/local/lib/ruby/gems/1.8/gems/activesupport-3.0.0.beta4/lib/active_support/dependencies.rb:198:in `load_dependency'
    from /usr/local/lib/ruby/gems/1.8/gems/activesupport-3.0.0.beta4/lib/active_support/dependencies.rb:554:in `new_constants_in'
    from /usr/local/lib/ruby/gems/1.8/gems/activesupport-3.0.0.beta4/lib/active_support/dependencies.rb:198:in `load_dependency'
    from /usr/local/lib/ruby/gems/1.8/gems/activesupport-3.0.0.beta4/lib/active_support/dependencies.rb:208:in `load'



However,
When I reset the search path to the public schema and attempt to load the file it works flawlessly.
 
Does anyone have any idea what might be the problem? Or perhaps, someone has some ideas or online resources about creating new postgresql schemas from within a rails application?

Any help will be much appreciated.

Thanks,
Mike

[Marnen Laibow-Koser]

mgerst...@gmail.com wrote:
> Hi All,
>
> Has anyone worked with Rails 3 and Postgresql schemas?

I don't think Rails 2 supports them. Has that changed in 3?

> I'm working on a
> multi-tenant Rails3 (beta 4) application where each account will have
> it's
> own schema in a postgresql database.

I cringe every time I see this. Just put all the data together -- it
will be much easier to manipulate.
--
Posted via http://www.ruby-forum.com/.

[Kym M.]

This is fixed in Rails 3.0.8+ and soon into 3.1