“约束”的问题

[lihan2001]

这样的约束怎样实现：在一个表中，用两个字段联合起来来确定某一条记录的唯一性？？？？

[伍子V5]

触发器

[伍子V5]

哈哈，在你这里升星成功

[txlicenhe]

恭喜letsflytogether(恨！不能拥有天下所有的财富，然后平分)升星。

[lihan2001]

提示一下怎么做，举个精简的例子，谢谢！！

[welyngj]

for example:
create table tbl
( a int not null,
b int not null,
c varchar(10),
constraint pk_tbl primary key(a,b))
insert into tbl values(1,2,'aa')
insert into tbl values(1,2,'ab')
违反了 PRIMARY KEY 约束 'pk_tbl'。不能在对象 'tbl' 中插入重复键。
语句已终止。

[txlicenhe]

eg:
CREATE TABLE [bod_det] (
[bod_fxdm] [varchar] (15) COLLATE Chinese_PRC_CI_AS NOT NULL ,
[bod_zxdm] [varchar] (15) COLLATE Chinese_PRC_CI_AS NOT NULL ,
[bod_dwyl] [numeric](9, 5) NULL CONSTRAINT [DF_bod_det_bod_dwyl] DEFAULT (1),
[bod_ksrq] [smalldatetime] NULL CONSTRAINT [DF_bod_det_bod_ksrq] DEFAULT (getdate()),
[bod_sxrq] [smalldatetime] NULL CONSTRAINT [DF_bod_det_bod_sxrq] DEFAULT (2009 - 12 - 31),
[bod_shjs] [numeric](18, 0) NULL ,
[bod_xh] [tinyint] NOT NULL ,
[bod_bzl] [varchar] (20) COLLATE Chinese_PRC_CI_AS NULL CONSTRAINT [DF_bod_det_bod_bzl] DEFAULT (''),
CONSTRAINT [PK_bod_det] PRIMARY KEY CLUSTERED
(
[bod_fxdm],
[bod_zxdm]
) ON [PRIMARY] ,
CONSTRAINT [FK_bod_det_bom_mstr] FOREIGN KEY
(
[bod_fxdm]
) REFERENCES [bom_mstr] (
[bom_fxdm]
),
CONSTRAINT [FK_bod_det_itm_mstr] FOREIGN KEY
(
[bod_zxdm]
) REFERENCES [itm_mstr] (
[itm_wldm]
),
CONSTRAINT [CK_bod_det] CHECK ([bod_dwyl] > 0)
) ON [PRIMARY]
GO

[Wally_wu]

不明白楼主意思

[hdslah]

把這兩字段設在聯合主鍵