What are some examples of Ruby on Rails migrations?

What are some examples of Ruby on Rails migrations?

Ruby on Rails migrations are used to modify your database schema. For example, to create a new table, you can use:

class CreateUsers < ActiveRecord::Migration[6.0]
  def change
    create_table :users do |t|
      t.string :name
      t.string :email
      t.timestamps
    end
  end
end

This migration creates a 'users' table with 'name' and 'email' fields.

Can you show me how to add a column to an existing table?

Certainly! To add a column to an existing table, you can create a migration like this:

class AddAgeToUsers < ActiveRecord::Migration[6.0]
  def change
    add_column :users, :age, :integer
  end
end

This will add an 'age' column of type integer to the 'users' table.

What about removing a column?

To remove a column, you can use the following migration:

class RemoveAgeFromUsers < ActiveRecord::Migration[6.0]
  def change
    remove_column :users, :age, :integer
  end
end

This will remove the 'age' column from the 'users' table.

How do I run these migrations?

You can run your migrations using the command:

rails db:migrate

This will apply all pending migrations to your database.