数据库图书馆课程设计

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[FK_Borrow_Info_Book_Info]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[Borrow_Info] DROP CONSTRAINT FK_Borrow_Info_Book_Info GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[FK_Borrow_