More that one db

rubyonrails-talk
1

Bahadır Doğan wrote:

Hello,

Sometimes I need to work with more than one databases. When I look at database.yml file, I see that only one database is specified. Is it possible to work with more than one databases?

Yes you can. In your database.yml file setup a new entry. E.g.:

legacy:    adapter: mysql    database: legacy    ...

In your model use "establish_connection :<database_entry>". E.g.:

class Departments < ActiveRecord::Base    establish_connection :legacy    ...

2

Just be aware that AR (like most LAMP stuff, afaik) doesn't support distributed transactions. When you start modifying multiple databases at once, data integrity is no longer guaranteed.

Isak

3

what does it mean "modifying multiple databases at once" ?

Let me rephrase: You can't make a transaction span multiple databases using AR (or Ruby in general, as far as i know).

If that's a requirement, your best bet is probably handing the work over to a Java web service or something along those lines. Then again, this may not be neccessary for your application.

Isak