# Migration in Multiple Database

**URL:** <https://www.ruby-forum.com/t/migration-in-multiple-database/171933>\
**Category:** Rails\
**Created:** [July 11, 2009, 6:58pm UTC](https://www.ruby-forum.com/t/migration-in-multiple-database/171933 "2009-07-11T18:58:09Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![virendra](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/e68b1a/32.png) [@virendra](https://www.ruby-forum.com/u/virendra)\
**Post date:** [July 11, 2009, 6:58pm UTC](https://www.ruby-forum.com/t/migration-in-multiple-database/171933/1 "2009-07-11T18:58:09Z")

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hello to all  
I been working on this from past few days.  
.I am talking about separate migration for each one of the multiple  
database that a single rails application has connection with.I know that  
rails can work with multiple databases but what with migrations  
for e.g  
my main rails application has a connection to two databases  
1\> main\_development  
2\> secondary\_development

Know suppose i have to create a new migration for my secondary database  
how do i do it

thanks to everyone

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<div class="post-metadata">

**Author:** ![virendra](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/e68b1a/32.png) [@virendra](https://www.ruby-forum.com/u/virendra)\
**Post date:** [July 12, 2009, 5:12am UTC](https://www.ruby-forum.com/t/migration-in-multiple-database/171933/2 "2009-07-12T05:12:28Z")

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Virendra N. wrote:

> my main rails application has a connection to two databases  
> 1\> main\_development  
> 2\> secondary\_development
> 
> Know suppose i have to create a new migration for my secondary database  
> how do i do it

I’ll trade you! This is how you do migrations. Change the declaration of  
all of your applicable migrations:

class MyMigration \< SecondaryDevelopmentMigration  
… the remainder of your migration …

# Put this somewhere convenient:

class SecondaryDevelopmentMigration \< ActiveRecord::Migration  
def self.connection  
SecondaryDevelopment.connection  
end  
end

Your turn! How do you handle test fixtures for your second database?

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<div class="post-metadata">

**Author:** ![virendra](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/e68b1a/32.png) [@virendra](https://www.ruby-forum.com/u/virendra)\
**Post date:** [July 12, 2009, 5:09pm UTC](https://www.ruby-forum.com/t/migration-in-multiple-database/171933/3 "2009-07-12T17:09:28Z")

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Adam Ms. wrote:  
[…]

> Your turn! How do you handle test fixtures for your second database?

Test fixtures are evil. Use factories instead (I’m fond of Machinist  
for this).

## Best,

Marnen Laibow-Koser  
[http://www.marnen.org](http://www.marnen.org)  
removed\_email\_address@domain.invalid

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<div class="post-metadata">

**Author:** ![virendra](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/e68b1a/32.png) [@virendra](https://www.ruby-forum.com/u/virendra)\
**Post date:** [July 12, 2009, 6:37pm UTC](https://www.ruby-forum.com/t/migration-in-multiple-database/171933/4 "2009-07-12T18:37:38Z")

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Adam Ms. wrote:

> Virendra N. wrote:
> 
> > my main rails application has a connection to two databases  
> > 1\> main\_development  
> > 2\> secondary\_development
> > 
> > Know suppose i have to create a new migration for my secondary database  
> > how do i do it
> 
> I’ll trade you! This is how you do migrations. Change the declaration of  
> all of your applicable migrations:
> 
> class MyMigration \< SecondaryDevelopmentMigration  
> … the remainder of your migration …
> 
> # Put this somewhere convenient:
> 
> class SecondaryDevelopmentMigration \< ActiveRecord::Migration  
> def self.connection  
> SecondaryDevelopment.connection  
> end  
> end
> 
> Your turn! How do you handle test fixtures for your second database?

Sorry i didn’t get that could you please explain me one more time with  
good e.g  
thank anyway