Rails and Databases

Rails
1

Hi Everyone,

I have a couple of questions

  1. A typical rails environment has 3 databases - development, test,
    production.
  • Can I have more?
  • Is there a limit?
  1. In most rails applications you usually have one database type i.e.
    MySQL or sqlite3 or PostgreSQL or …
  • Can I use MySQL and sqlite3 from the same rails application?
  • Is there a limit?

Regards

2

we can use multiple database in one rails app.
here’s the example :
database.yml
development:

adapter: mysql
username: root
password:
database: example_development

oracle_development:
adapter: oracle
username: root

password:
database: example_oracle_developmen
in the model :
class User < ActiveRecord::Base

establish_connection :oracle_development
end

class Address < ActiveRecord::Base

establish_connection :development
end
So, based on this code you can have more than 3 database in 1 rails
app.

That’s my none scientific explanation.
thanks.

3

As a usage note, create an abstract base class with the connection you
want and inherit the children (models) from this base class for
connection pooling to work properly. If you don’t, your database may
end up with one connection per model in your code.

class OracleConnectBase < ActiveRecord::Base
establish_connection :xyz
@abstract_class = true
end

class User < OracleConnectBase

life goes on

end

Regards,
Mukund

4

On Aug 23, 2009, at 9:29 PM, GuruOne wrote:

Hi Everyone,

I have a couple of questions

  1. A typical rails environment has 3 databases - development, test,
    production.
  • Can I have more?
  • Is there a limit?

David and Mukund seem to have answered your second question. I’ll
focus on this one.

I’d rephrase your question a bit:

  1. A typical rails application defines three environments -
    development, test, production.

  • Can I define others?

    Yes, you can. I’ve had “staging”, “fabrication”, and
    “production_LIVE” environments on various projects in addition to the
    standard three.

  • Is there a limit?

    No, not really. You do have to keep a config/environments/staging.rb
    (or whatever your environment is called) and the corresponding section
    of the database.yml file, but that doesn’t put a limit on how many
    environments you can have. The real limit is probably your ability to
    give them names that you can keep straight.

-Rob

Rob B. http://agileconsultingllc.com
[email protected]

5

Thxs.

6

Thxs

7

Dear Rob,

Thxs.

Regards
On Aug 24, 9:08 am, Rob B. [email protected]