如何在C#中将密钥设为外国 [英] How to make key foreign in c#

问题描述

朋友，我是bishnu
我有一个项目，我想做一个外键，这是另一个表中的主键

像..........一个表的表名为tblEmployee，其中Employeeid为主键，而我的另一个表为tblAttendance，其中，希望Employeeid为外键.我正在使用sqlserver express2005.请尽快提供查询或代码帮助?

hi friends, i m bishnu
i have a project and i want to make a foreign key which is primary key in another table

like.......... one table has table name tblEmployee where Employeeid is primary key and i have another table tblAttendance where Employeeid is wished to be made foreign key. i am using sqlserver express 2005. please help with query or code as soon as possible?

推荐答案

解决方案在于SQL，而不是c#.

您可以通过以下方式向您的字段添加外键:

Hi,

The solution lies in SQL, not in c#.

You can add a foreign key to your field this way :

ALTER TABLE [tblAttendance]
ADD CONSTRAINT [FK_tblAttendance_tblEmployee]
FOREIGN KEY [Employeeid]
REFERENCES [tblEmplyee] ([Employeeid])
ON DELETE NO ACTION ON UPDATE NO ACTION;
GO

建议您在外键上也加一个索引:

It is advised to also put an index on your foreign key :

CREATE INDEX [IX_FK_tblAttendance_tblEmployee]
ON [tblAttendance] ([Employeeid]);
GO

如果您正在谈论DataRelation对象，请检查论坛讨论 [ ^ ]应该可以为您提供帮助.

If you are talking about DataRelation objects, then check this[^] out.

If you want to do this through code (for a table), then this forum discussion[^] should help you out.

如果在创建表时不使用该表，是否已经创建了该表. .......

试试这个查询

创建表tblAttendance
(
Employeeid data_type外键引用tblEmployee(Employeeid)，
other_col data_type
)

如果已经创建了表，请使用philo先生建议的alter table
并尝试Abhinav先生提供的链接
祝你好运........

Have you created the table already if no use this when you create it.........

Try this query

create table tblAttendance
(
Employeeid data_type foreign key refrences tblEmployee(Employeeid),
other_col data_type
)

In case table is already created use alter table as suggested by Mr philo
and try links provided by Mr Abhinav
Best of luck........

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