我如何使用外键 [英] How I use Foreign Key

问题描述

嗨





有人请告诉我如何使用外键

Hi


Somebody please tell me how i use foreign key

推荐答案

有关您问题的所有信息...

http：// www.1keydata.com/sql/sql-foreign-key.html [ ^ ]

all information regarding your question ...
http://www.1keydata.com/sql/sql-foreign-key.html[^]

如何使用？通常......建立桌子之间的关系。



见这个：

http://www.w3schools.com/sql/sql_foreignkey.asp [ ^ ]

创建外键关系 [ ^ ]

How to use? Normally... to build relationship between tables.

See this:
http://www.w3schools.com/sql/sql_foreignkey.asp[^]
Create Foreign Key Relationships[^]

在2表，主表和从表之间创建关系时。您使用外键作为字段来创建关系。



在您的代码中（来自您的评论）很明显，整数ID将是一个FOREIGN KEY。正如 Microsoft SQL Server文档 [ ^ ]说，

When you create a relationship between 2 table, a master and a slave table. You use a foreign key to be used as a field to create the relationship on.

In your code (from your comment) it is clear that the ID that integer, would be a FOREIGN KEY. As Microsoft SQL Server documentation[^] says,

Quote：

外键（FK）是一列或列的组合，用于在两个表中的数据之间建立和实施链接。您可以在创建或修改表时通过定义FOREIGN KEY约束来创建外键。

A foreign key (FK) is a column or combination of columns that is used to establish and enforce a link between the data in two tables. You can create a foreign key by defining a FOREIGN KEY constraint when you create or modify a table.

阅读附加链接，它有更多信息本章，你会在那里找到更多细节。



谢谢。

Read the attached link, it has more information on this chapter and you will find more details to it there.

Thanks.

这篇关于我如何使用外键的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！