Run a single migration file

Question

Is there an easy way to run a single migration  I don t want to migrate to a certain version I just want to run a specific one

User · Answer

If you want to run a specific migration  do    rake db migrate up VERSION 20080906120000   If you want to run migrations multiple times  do    use the STEP parameter if you need to go more than one version back   rake db migrate redo STEP 3   If you want to run a single migration multiple times  do    this is super useful   rake db migrate redo VERSION 20080906120000    you can find the version number in the filename of your migration     Edit  You can also simply rename your migration file  Eg    20151013131830 my migration rb -  20151013131831 my migration rb  Then migrate normally  this will treat the migration as a new one  usefull if you want to migrate on a remote environment  such as staging  on which you have less control   Edit 2  You can also just nuke the migration entry in the database  Eg   rails c gt  q    delete from schema migrations where version    20151013131830   rails c gt  ActiveRecord  Base connection execute q    rake db migrate will then rerun the up method of the nuked migrations

User · Answer

This are the steps to run again this migration file  20150927161307 create users rb    Run the console mode   rails c  Copy and past the class which is in that file to the console   class CreateUsers  lt  ActiveRecord  Migration   def change     create table  users do  t        t string  name       t string  email       t timestamps null  false   end     end   end end  Create an instance of the class CreateUsers  c1   CreateUsers new Execute the method change of that instance  c1 change

User · Answer

Looks like at least in the latest Rails release  5 2 at the time of writing  there is one more way of filtering the migrations being ran  One can pass a filter in a SCOPE environment variable which would be then used to select migration files    Assuming you have two migration files 1 add foos rb and 2 add foos run this one rb running  SCOPE run this one rails db migrate up   will select and run only 2 add foos run this one rb  Keep in mind that all migration files matching the scope will be ran

User · Answer

If you ve implemented a change method like this   class AddPartNumberToProducts  lt  ActiveRecord  Migration   def change     add column  products   part number   string   end end   You can create an instance of the migration and run migrate  up  or migrate  down  on an instance  like this     rails console  gt  gt  require  db migrate 20090408054532 add part number to products rb   gt  gt  AddPartNumberToProducts new migrate  down

User · Answer

As of rails 5 you can also use rails instead of rake  Rails 3 - 4     lt  rails-5 0 rake db migrate up VERSION 20160920130051   Rails 5      gt   rails-5 0 rake db migrate up VERSION 20160920130051    or  rails db migrate up VERSION 20160920130051

User · Answer

If you want to run it from console  this is what you are looking for     rails console irb main  gt  require    Rails root to s  db migrate XXXXX my migration rb  irb main  gt  AddFoo migrate  up    I tried the other answers  but requiring without Rails root didnt work for me   Also   migrate  up  part forces the migration to rerun regardless if it has already run or not  This is useful for when you already ran a migration  have kinda undone it by messing around with the db and want a quick solution to have it up again

User · Answer

Please notice that instead of script runner  you may have to use rails runner on new rails environments

User · Answer

Method 1    rake db migrate up VERSION 20080906120000   Method 2    In Rails Console  1  Copy paste the migration class in console  say add name to user rb   2  Then in console  type the following  Sharding run on all shards AddNameToUser up    It is done

User · Answer

If you re having trouble with paths you can use  require Rails root    db migrate 20090408054532 add foos rb

User · Answer

Assuming fairly recent version of Rails you can always run   rake db migrate up VERSION 20090408054532   Where version is the timestamp in the filename of the migration   Edit  At some point over the last 8 years  I m not sure what version  Rails added checks that prevent this from running if it has already been run   This is indicated by an entry in the schema migrations table   To re-run it  simply execute rake db migrate redo VERSION 20090408054532 instead

User · Answer

You can just run the code directly out of the ruby file  rails console  gt  gt  require  quot db migrate 20090408054532 add foos rb quot   gt  gt  AddFoos new up  Note  Very old versions of rails may require AddFoos up rather than AddFoos new up  An alternative way  without IRB  which relies on the fact that require returns an array of class names  script runner  require  quot db migrate 20090408054532 add foos rb quot   first constantize up   Note that if you do this  it won t update the schema migrations table  but it seems like that s what you want anyway  Additionally  if it can t find the file you may need to use require  quot   db     quot  or try require relative depending on your working directory

[ruby-on-rails] Run a single migration file

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