CODEWITHSUNDEEP
ruby-on-railsrubyactiverecord
Steve
Steve

Reputation: 464

How do I rollback to a previous migration and delete tables and columns in my schema?

I'm working on a Rails 5 project and I've added various columns to some of my tables and created a new table as well. This obviously has created a few migration files and I would like to revert back to a certain migration and delete all the changes in the schema that were made after this migration. How do I do this?

Schema.rb: 

ActiveRecord::Schema.define(version: 20180814220216) do

  create_table "stores", force: :cascade do |t|
    t.string "name"
    t.string "address"
    t.float "beer_cost"
    t.text "facilities"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
    t.float "latitude"
    t.float "longitude"
    t.boolean "toilet"
    t.string "address_line2"
    t.string "address_line3"
    t.integer "user_id"
    t.integer "toilet_id"
    t.string "toilet_available"
  end

  create_table "toilets", force: :cascade do |t|
    t.string "toilet_available"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

  create_table "users", force: :cascade do |t|
    t.string "email", default: "", null: false
    t.string "encrypted_password", default: "", null: false
    t.string "reset_password_token"
    t.datetime "reset_password_sent_at"
    t.datetime "remember_created_at"
    t.integer "sign_in_count", default: 0, null: false
    t.datetime "current_sign_in_at"
    t.datetime "last_sign_in_at"
    t.string "current_sign_in_ip"
    t.string "last_sign_in_ip"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
    t.index ["email"], name: "index_users_on_email", unique: true
    t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true
  end

end

Output after running rails db:migrate:status

 Status   Migration ID    Migration Name
--------------------------------------------------
   up     20180610144440  Create stores
   up     20180611145310  Change datatype beer cost
   up     20180611150425  Delete cig cost column
   up     20180611231832  Add longitude and latitude
   up     20180612194032  Add toilets column
   up     20180614125348  Add address line2 column
   up     20180614133234  Add address line3 column
   up     20180625201708  Devise create users
   up     20180625235156  Add user id to stores
   up     20180626124327  ********** NO FILE **********
   up     20180626124742  ********** NO FILE **********
   up     20180627115344  ********** NO FILE **********
   up     20180627115710  ********** NO FILE **********
   up     20180810102513  ********** NO FILE **********
   up     20180811094301  ********** NO FILE **********
   up     20180814220216  ********** NO FILE **********

Upvotes: 2

Views: 3171

Answers (2)

user229044
user229044

Reputation: 239270

You should not have deleted the migrations, once you've deleted them, you cannot roll them back. The correct sequence of steps is to rake db:rollback, then delete the migration file.

At this point the simplest solution is to use rails db to open an SQL terminal, and manually drop the columns/tables you don't want, and then rake db:schema:dump to update your schema.rb.

Upvotes: 1

Amiratak88
Amiratak88

Reputation: 1509

You can use: rails db:rollback STEP=<put the number of migrations you want to go back

However the migrations are still there and if you run rails db:migrate you are still gonna see all those changes.

So either write new migrations that undo the previous migrations, delete the table for instance.

Or delete the unwanted migration files manually.

Upvotes: 2

Related Questions