class CQL::Migration

Reference < Object

Migrations are used to manage changes to the database schema over time. Each migration is a subclass of Migration and must implement the up and down methods. The up method applies the migration, while the down method rolls back the migration.

Migrations are executed in version order, and the Migrator class manages them, providing methods to apply, roll back, and track migrations.

Example: Creating a Migration

class AddEmailToUsers < CQL::Migration
  def up
    schema.alter_table(:users) do
      add_column :email, String
    end
  end

  def down
    schema.alter_table(:users) do
      drop_column :email
    end
  end
end

Methods

def up

Defines the operations to apply when the migration is run.

• @return [Nil]

Example:

def up
  schema.alter_table(:users) do
    add_column :email, String
  end
end

def down

Defines the operations to roll back the migration.

• @return [Nil]

Example:

def down
  schema.alter_table(:users) do
    drop_column :email
  end
end