例:
class CreateLineItems < ActiveRecord::Migration
def self.up
create_table :line_items do |t|
t.column :product_id, :integer, :null=>false
t.column :order_id, :integer, :null=>false
t.column :quantity, :integer, :null=>false
t.column :total_price, :decimal, :null=>false, :precision => 8, :scale => 2
end
execute "alter table line_items
add constraint fk_line_item_products
foreign key(product_id) references products(id)"
execute "alter table line_items
add constraint fk_line_item_orders
foreign key(order_id) references orders(id)"
end
def self.down
execute "alter table line_items
drop foreign key fk_line_item_products"
execute "alter table line_items
drop foreign key fk_line_item_orders"
drop_table :line_items
end
end
def self.up
create_table :line_items do |t|
t.column :product_id, :integer, :null=>false
t.column :order_id, :integer, :null=>false
t.column :quantity, :integer, :null=>false
t.column :total_price, :decimal, :null=>false, :precision => 8, :scale => 2
end
execute "alter table line_items
add constraint fk_line_item_products
foreign key(product_id) references products(id)"
execute "alter table line_items
add constraint fk_line_item_orders
foreign key(order_id) references orders(id)"
end
def self.down
execute "alter table line_items
drop foreign key fk_line_item_products"
execute "alter table line_items
drop foreign key fk_line_item_orders"
drop_table :line_items
end
end
本文转自 fsjoy1983 51CTO博客,原文链接:http://blog.51cto.com/fsjoy/89042,如需转载请自行联系原作者