Class: Sequel::Migration

Sequel‘s older migration class, available for backward compatibility. Uses subclasses with up and down instance methods for each migration:

  Class.new(Sequel::Migration) do
    def up
      create_table(:artists) do
        primary_key :id
        String :name
      end
    end

    def down
      drop_table(:artists)
    end
  end

Part of the migration extension.

Methods

apply descendants down inherited method_missing new up

Public Class methods

apply(db, direction)

Applies the migration to the supplied database in the specified direction.

[Source]

    # File lib/sequel/extensions/migration.rb, line 31
31:     def self.apply(db, direction)
32:       raise(ArgumentError, "Invalid migration direction specified (#{direction.inspect})") unless [:up, :down].include?(direction)
33:       new(db).send(direction)
34:     end

descendants()

Returns the list of Migration descendants.

[Source]

    # File lib/sequel/extensions/migration.rb, line 37
37:     def self.descendants
38:       @descendants ||= []
39:     end

inherited(base)

Adds the new migration class to the list of Migration descendants.

[Source]

    # File lib/sequel/extensions/migration.rb, line 42
42:     def self.inherited(base)
43:       descendants << base
44:     end

new(db)

Creates a new instance of the migration and sets the @db attribute.

[Source]

    # File lib/sequel/extensions/migration.rb, line 25
25:     def initialize(db)
26:       @db = db
27:     end

Public Instance methods

down()

The default down action does nothing

[Source]

    # File lib/sequel/extensions/migration.rb, line 47
47:     def down
48:     end

method_missing(method_sym, *args, &block)

Intercepts method calls intended for the database and sends them along.

[Source]

    # File lib/sequel/extensions/migration.rb, line 51
51:     def method_missing(method_sym, *args, &block)
52:       @db.send(method_sym, *args, &block)
53:     end

up()

The default up action does nothing

[Source]

    # File lib/sequel/extensions/migration.rb, line 56
56:     def up
57:     end