rails db：migrate rails已中止！ Mysql2 :: Error：用户'root'@'localhost'的访问被拒绝（使用密码：是）

Question

I'm running this migration:

class CreateAdmins < ActiveRecord::Migration[5.1]
  def change
    create_table :admins do |t|

      t.string "first_name" :limit => 30
      t.string "last name", :limit => 30
      t.string "email", :default => '', :null => false
      t.string "password" ,:limit => 40
      t.timestamps

    end
  end

  def down
    drop_table :admins
  end
end

I get an error saying:

rails db:migrate rails aborted! Mysql2::Error: Access denied for user 'root'@'localhost' (using password: YES)

Answer 1

You should update your database.yml file, in the config-directory. The error is caused by mysql responding with an authentication error, for your root user. You might wanna check http://edgeguides.rubyonrails.org/configuring.html#configuring-a-database for information on the database.yml syntax.

You can furthermore check and validate the login in shell by running mysql -u root -p and try entering your password.

Answer 2

For the first, this is correct migration code:

class CreateAdmins < ActiveRecord::Migration[5.1]
  def self.up
    create_table :admins do |t|
      t.string :first_name, limit: 30
      t.string :last_name, limit: 30
      t.string :email, default: '', null: false
      t.string :password ,limit: 40

      t.timestamps
    end
  end

  def self.down
    drop_table :admins
  end
end

or just change difference

class CreateAdmins < ActiveRecord::Migration[5.1]
  def change
    create_table :admins do |t|
      t.string :first_name, limit: 30
      t.string :last_name, limit: 30
      t.string :email, default: '', null: false
      t.string :password ,limit: 40

      t.timestamps
    end
  end
end

About error, your database.yml for development env, should looks like this:

development:
  adapter: mysql2
  encoding: utf8
  database: your_db_name
  username: your_user
  password: your_password
  host: 127.0.0.1
  port: 3306