InlineMigrations module

A plugin for Sequel::Model that allows migrations for the model to be defined directly in the class declaration. It uses the inline_schema plugin internally, and will add it for you if necessary.

Example

Define a base (abstract) model class:

# lib/acme/model.rb
module Acme
    Model = Class.new( Sequel::Model )
    Model.def_Model( Acme )

    class Model
        plugin :inline_schema
        plugin :inline_migrations
    end
end

Defining a model class with two migrations:

# lib/acme/vendor.rb
require 'acme/model'

class Acme::Vendor < Acme::Model( :vendor )

    # The schema should always be kept up-to-date. I.e., it should be
    # modified along with each migration to reflect the state of the table
    # after the migration is applied.
    set_schema do
        primary_key :id
        String :name
        String :contact
        timestamp :created_at, :null => false
        timestamp :updated_at

        add_index :name
    end

    # Similar to Sequel's TimeStampMigrator, inline migrations have a symbolic
    # name, which is how they're tracked in the migrations table, and how
    # they're ordered when they're applied. The second argument is a human-readable
    # description that can be used for automated change control descriptions or
    # other tooling.
    migration( '20110228_1115_add_timestamps', "Add timestamp fields" ) do
        change do
            alter_table do
                add_column :created_at, :timestamp, :null => false
                add_column :updated_at, :timestamp
            end
            update( :created_at => :now[] )
        end
    end

    migration( '20110303_1751_index_name', "Add an index to the name field" ) do
        change do
            alter_table do
                add_index :name
            end
        end
    end

end

Apply pending migrations.

# bin/migrate

require 'acme/model'
require 'acme/vendor'
# ...

puts "Creating new tables, applying any pending migrations..."
Acme::Model.migrate

Notable Model Methods

See Sequel::Plugins::InlineSchema::ClassMethods for documentation for the methods the plugin adds to your model class/es.

• migration – define a migration

• migrate – create any missing tables for the receiving model and any subclasses, then run any unapplied migrations.

Inline migrations also have model hook methods:

• before_migration

• after_migration

There’s also a method that will return a configured Sequel::Plugins::InlineMigrations::Migrator in case you want to inspect what will happen when you call migrate:

• migrator