求解释语句。解决思路
日期：2014-05-18 浏览次数：20519 次
求解释语句。
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[订货表]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [dbo].[订货表]
GO
CREATE TABLE [dbo].[订货表] (
[订单编号] [int] IDENTITY (1, 1) NOT NULL ,
[书籍编号] [int] NOT NULL ,
[数量] [smallint] NOT NULL ,
[折扣] [real] NOT NULL ,
[单价] [money] NULL ,
[销售金额] AS ([单价] * [数量] * [折扣])
) ON [PRIMARY]
GO
------解决方案--------------------
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[订货表]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [dbo].[订货表]
GO
CREATE TABLE [dbo].[订货表] (
[订单编号] [int] IDENTITY (1, 1) NOT NULL ,
[书籍编号] [int] NOT NULL ,
[数量] [smallint] NOT NULL ,
[折扣] [real] NOT NULL ,
[单价] [money] NULL ,
[销售金额] AS ([单价] * [数量] * [折扣])
) ON [PRIMARY]
GO
------解决方案--------------------
- SQL code
--如果存在订货表
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[订货表]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
--删除订货表
drop table [dbo].[订货表]
GO
--创建订货表
CREATE TABLE [dbo].[订货表] (
[订单编号] [int] IDENTITY (1, 1) NOT NULL , --自增列
[书籍编号] [int] NOT NULL ,
[数量] [smallint] NOT NULL ,
[折扣] [real] NOT NULL ,
[单价] [money] NULL ,
[销售金额] AS ([单价] * [数量] * [折扣]) --计算列
) ON [PRIMARY]
GO
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