Rails - Aug 2009 - rake db:schema:load insists on querying my database for data I haven't loaded.

Rails 2.3.2.  Ruby 1.8.7.  MySQL 5.x

I have used "rake db:schema:dump" to generate a migration structure to
go from development to production.  I want to use "rake
db:schema:load" to load it into my new database.  Sounds like a plan.

When I run "rake db:schema:load" on the new database (development or
production), I get the following error:

<from development test>
rake aborted!
Mysql::Error: Table ''mojo_development.statuses''
doesn''t exist: SELECT
* FROM `statuses` WHERE (`statuses`.`name` = ''New'')  LIMIT 1

(production gives the same, but database name is mojo_production).

The Select is not in the schema.  If I trace it back, I find the
Select is generated from the following method in my Mojo model:


  def self.new_state
    for_name(''New'').first
  end

where for_name is a :named_scope generating the select statement
above.


So my questions are:

1) WHY does db:schema:load run queries against my database when the
data (and tables) aren''t there?

and

2) HOW do I fix this so it won''t happen again?

Posting the results of running the rake command with --trace always
helps, but I''d say the likely culprit here is something in your
environment / initializers. Does that function get called from
environment.rb or an initializer?

--Matt Jones

On Aug 11, 12:31 am, Polydectes
<esmith...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> Rails 2.3.2.  Ruby 1.8.7.  MySQL 5.x
>
> I have used "rake db:schema:dump" to generate a migration
structure to
> go from development to production.  I want to use "rake
> db:schema:load" to load it into my new database.  Sounds like a plan.
>
> When I run "rake db:schema:load" on the new database (development
or
> production), I get the following error:
>
> <from development test>
> rake aborted!
> Mysql::Error: Table ''mojo_development.statuses''
doesn''t exist: SELECT
> * FROM `statuses` WHERE (`statuses`.`name` = ''New'')
 LIMIT 1
>
> (production gives the same, but database name is mojo_production).
>
> The Select is not in the schema.  If I trace it back, I find the
> Select is generated from the following method in my Mojo model:
>
>   def self.new_state
>     for_name(''New'').first
>   end
>
> where for_name is a :named_scope generating the select statement
> above.
>
> So my questions are:
>
> 1) WHY does db:schema:load run queries against my database when the
> data (and tables) aren''t there?
>
> and
>
> 2) HOW do I fix this so it won''t happen again?

Eric Smith wrote:
> Rails 2.3.2.  Ruby 1.8.7.  MySQL 5.x
> 
> I have used "rake db:schema:dump" to generate a migration
structure to
> go from development to production.  I want to use "rake
> db:schema:load" to load it into my new database.  Sounds like a plan.
> 
> When I run "rake db:schema:load" on the new database (development
or
> production), I get the following error:
> 
Your rake task is picking up your development environment from 
config/environment.rb.

Here''s what you can do to start off with a clean production schema 
provided you are the only one working on your db and you have 
foolishly/wisely modified your db schema without going through a proper 
migration strategy..

1) perform a rake db:schema:dump
2) remove all prior migration files
3) perform a rake db:migrate
4) open the migration file just created, and cut and paste the contents 
from the schema.rb file that you created in step 1.  (during the paste, 
just copy the relevant parts, avoid the database create part..)
5) Now you can use that migration file on production
6) Ask that girl in finance out on a date like you promised yourself 2 
weeks ago.

hth

ilan

-- 
Posted via http://www.ruby-forum.com/.

On Aug 11, 5:31 am, Polydectes
<esmith...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> 1) WHY does db:schema:load run queries against my database when the
> data (and tables) aren''t there?
>
> and
>
> 2) HOW do I fix this so it won''t happen again?
rake db:schema:load requires the environment task (which loads your
app config and so on)
in production config.cache_classes is true, which means that your
applications models are loaded
your Mojo model is loaded, and reaches the line

named_scope :some_scope, :conditions => {.... self.new_state }

which runs your new_state ,method, which queries the database

One possible solution: alter your environment so that cache classes
doesn''t get set to true in cases like this. I outlined a few ways of
doing this at
http://www.spacevatican.org/2008/12/28/when-cache_classes-gets-you-down

Fred