Running single migration file

Rails
1

hi all,

     in my db/migrate folder im having many migrations files that

creates tables,add columns,and remove columns.i created a new migration
file now and can i run only this new migration file using rake
command.how to run a specific migration using rake command.people know
it help me please.

2

On Apr 29, 2008, at 3:28 AM, Karthikragunath B. wrote:

hi all,

    in my db/migrate folder im having many migrations files that

creates tables,add columns,and remove columns.i created a new
migration
file now and can i run only this new migration file using rake
command.how to run a specific migration using rake command.people know
it help me please.

You can do:
rake db:migrate VERSION=12
to run the migrations necessary to get to version 12 from wherever you
are. If the database is at version 11, that will cause the 012_* up
migration to run, if at 13, the 012_* down migration will run. There
is no command to pluck a particular migration out of the middle and
run it (up or down).

Normally, you just add the migration and run: rake db:migrate
and it does the right thing. I tend to make a backup of the
development database and then run migrations forward VERSION=12 and
then backward VERSION=11 until I’m sure that the migration is
reversible (usually when there’s some non-trivial data-munging going
on).

-Rob

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

3

For specific updates you can manipulate the schema.rb file accordingly
and
load it.
rake db:schema:dump dumps the schema and load does the opposite.
So you can dump, include all the migration changes you want and load for
a
quick solution.

On Tue, Apr 29, 2008 at 12:58 PM, Karthikragunath B. <