Rails and Databases

rubyonrails-talk
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?

2. 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

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 Biedenharn http://agileconsultingllc.com Rob@AgileConsultingLLC.com

5

Dear Rob,

Thxs.

Regards

6

Thxs.

7

Thxs