Ruby on Rails ActiveRecord::PendingMigrationError - ruby-on-rails

Question

When I try to load my rails app on my localhost I get an error telling me to resolve it by running rails db:migrate but when I try to run the command this is what I get
C:\Sites\CoolGuyGear>rails db:migrate
== 20180108004216 AddDeviseToViews: migrating =================================
-- change_table(:views)
rails aborted!
StandardError: An error has occurred, this and all later migrations canceled:
SQLite3::SQLException: duplicate column name: email: ALTER TABLE "views" ADD "email" varchar DEFAULT '' NOT NULL
C:/Sites/CoolGuyGear/db/migrate/20180108004216_add_devise_to_views.rb:7:in `block in up'
C:/Sites/CoolGuyGear/db/migrate/20180108004216_add_devise_to_views.rb:5:in `up'
bin/rails:4:in `require'
bin/rails:4:in `<main>'
Caused by:
ActiveRecord::StatementInvalid: SQLite3::SQLException: duplicate column name: email: ALTER TABLE "views" ADD "email" varchar DEFAULT '' NOT NULL
C:/Sites/CoolGuyGear/db/migrate/20180108004216_add_devise_to_views.rb:7:in `block in up'
C:/Sites/CoolGuyGear/db/migrate/20180108004216_add_devise_to_views.rb:5:in `up'
bin/rails:4:in `require'
bin/rails:4:in `<main>'
Caused by:
SQLite3::SQLException: duplicate column name: email
C:/Sites/CoolGuyGear/db/migrate/20180108004216_add_devise_to_views.rb:7:in `block in up'
C:/Sites/CoolGuyGear/db/migrate/20180108004216_add_devise_to_views.rb:5:in `up'
bin/rails:4:in `require'
bin/rails:4:in `<main>'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)
Migration:
# frozen_string_literal: true
class AddDeviseToViews < ActiveRecord::Migration[5.1]
def self.up
change_table :views do |t|
## Database authenticatable
t.string :email, null: false, default: ""
t.string :encrypted_password, null: false, default: ""
## Recoverable
t.string :reset_password_token
t.datetime :reset_password_sent_at
## Rememberable
t.datetime :remember_created_at
## Trackable
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
## Confirmable
# t.string :confirmation_token
# t.datetime :confirmed_at
# t.datetime :confirmation_sent_at
# t.string :unconfirmed_email # Only if using reconfirmable
## Lockable
# t.integer :failed_attempts, default: 0, null: false # Only if lock strategy is :failed_attempts
# t.string :unlock_token # Only if unlock strategy is :email or :both
# t.datetime :locked_at
# Uncomment below if timestamps were not included in your original model.
# t.timestamps null: false
end
add_index :views, :email, unique: true
add_index :views, :reset_password_token, unique: true
# add_index :views, :confirmation_token, unique: true
# add_index :views, :unlock_token, unique: true
end
def self.down
# By default, we don't want to make any assumption about how to roll
#back a migration when your
# model already existed. Please edit below which fields you would like to remove in this migration.
raise ActiveRecord::IrreversibleMigration
end
end
create_table "views", 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_views_on_email", unique: true
t.index ["reset_password_token"], name:
"index_views_on_reset_password_token", unique: true
end

Answer 1

The answer is in the question.
Whatever migrations you have added are creating duplicate columns in your database as seen in the log generated from the migration.
duplicate column name: email: ALTER TABLE "views" ADD "email"
Create a migration that either removes those columns from your database or go directly into your local mysql/sqlite database and remove those columns manually. Run the migration again and, since you don't already have those columns in your database table, you will not receive these errors.