ruby on rails - How to remove the cancelled migration from the db folder -

i want remove migration application.

i have migration file 20141105030942_removedate_fromexpense.rb

the class file migrations

class removedatefromexpense < activerecord::migration   def change    remove_column :expenses, :date, :date   end end 

when give command:

rake db:migrate:down version=20141105030942 

i following error:

== 20141105030942 removedatefromexpense: reverting ============================ -- add_column(:expenses, :date, :date) rake aborted! standarderror: error has occurred, migration canceled:  sqlite3::sqlexception: duplicate column name: date: alter table "expenses" add "date" date/home/sumyvps/.rvm/gems/ruby-1.9.3-p545@railstutorial_rails_4_0/gems/sqlite3-1.3.8/lib/sqlite3/database.rb:91:in `initialize'  db:migrate:status migration file below     20141105030942  removedate fromexpense 

has idea why happening?

you not need specify column type in migration file. name of table , column enough remove column table.

edit migration file to:

class removedatefromexpense < activerecord::migration   def change    remove_column :expenses, :date   end end 

and run:

rake db:migrate 

this should work.