从 table 中移除 belongs_to 关系
Remove belongs_to relation from table
我想从定制礼服中删除 User
belongs_to
关系 table。
这是我的定制装扮迁移:
class CreateCustomisedDresses < ActiveRecord::Migration
def change
create_table :customised_dresses do |t|
t.belongs_to :user, index: true, null: :false
t.timestamps null: false
end
add_foreign_key :customised_dresses, :users, dependent: :delete
end
我尝试了以下迁移,但它给了我一个错误:
class RemoveForeignKeyUsersFromCustomisedDresses < ActiveRecord::Migration
def self.up
add_foreign_key :customised_dresses, :users
end
def self.down
remove_foreign_key :customised_dresses, :users
end
end
你应该在 up 和 down 方法中交换你的代码:
class RemoveForeignKeyUsersFromCustomisedDresses < ActiveRecord::Migration
def self.up
remove_foreign_key :customised_dresses, :users
end
def self.down
add_foreign_key :customised_dresses, :users
end
end
我想从定制礼服中删除 User
belongs_to
关系 table。
这是我的定制装扮迁移:
class CreateCustomisedDresses < ActiveRecord::Migration
def change
create_table :customised_dresses do |t|
t.belongs_to :user, index: true, null: :false
t.timestamps null: false
end
add_foreign_key :customised_dresses, :users, dependent: :delete
end
我尝试了以下迁移,但它给了我一个错误:
class RemoveForeignKeyUsersFromCustomisedDresses < ActiveRecord::Migration
def self.up
add_foreign_key :customised_dresses, :users
end
def self.down
remove_foreign_key :customised_dresses, :users
end
end
你应该在 up 和 down 方法中交换你的代码:
class RemoveForeignKeyUsersFromCustomisedDresses < ActiveRecord::Migration
def self.up
remove_foreign_key :customised_dresses, :users
end
def self.down
add_foreign_key :customised_dresses, :users
end
end