The title sums it up pretty much. Now you can do things like following.
class AddConstraintsToBooks < ActiveRecord::Migration
def self.up
constrain :books do |t|
t[:title, :author_id].all :unique => true # Notice how multiple columns are listed in brackets.
end
end
def self.down
deconstrain :books do |t|
t[:title, :author_id].all :unique
end
end
end
def self.up
constrain :books do |t|
t[:title, :author_id].all :unique => true # Notice how multiple columns are listed in brackets.
end
end
def self.down
deconstrain :books do |t|
t[:title, :author_id].all :unique
end
end
end
And here’s the foreign key example.
class AddConstraintsToBooks < ActiveRecord::Migration
def self.up
constrain :books do |t|
t.author_id :reference => {:authors => :id, :on_delete => :cascade} # :on_delete is optional
end
end
def self.down
deconstrain :books do |t|
t.author_id :reference
end
end
end
def self.up
constrain :books do |t|
t.author_id :reference => {:authors => :id, :on_delete => :cascade} # :on_delete is optional
end
end
def self.down
deconstrain :books do |t|
t.author_id :reference
end
end
end
