像我五岁一样解释->主键如何满足第一范式 [英] Explain Like I am Five -> How a Primary Key Satisfies First Normal Form

问题描述

谢谢您的预先了解。我正在为参加Microsoft技术考试而学习，其中一个实践问题是：

Thank you for your knowledge in advance. I am studying for the Microsoft Technology Exam and one of the practice questions is :

创建主键可以满足第一种标准形式。是真的还是假的？

Creating a primary key satisfies the first normal form. True or False?

我个人认为这是错误的，因为第一个范式是消除重复的组。但是文本（数据库基础知识，Microsoft Press考试98-364）中有一个句子，内容如下：

I personally think it is False because the first normal form is to get rid of duplicate groups. But there is a sentence in the text (Database Fundamentals, Exam 98-364 by Microsoft Press) that says the following:

第一个规范化形式（1NF）表示数据采用实体格式，这基本上意味着必须满足以下三个条件：
•该表必须没有重复的记录。为该表定义主键后，您已经满足了第一个规范化格式条件。

"The first normalized form (1NF) means the data is in an entity format, which basically means that the following three conditions must be met: • The table must have no duplicate records. Once you have defined a primary key for the table, you have met the first normalized form criterion."

请帮助我理解这一点，请像我五岁时那样进行解释。谢谢。

Please help me understand this, please explain like I am five. Thanks.

推荐答案

主键必须完全唯一。因此，一旦这成为记录的一部分，它便与任何其他记录都不同。

A primary key must be completely unique. So once this is part of a record, it is distinct from any other record.

例如。

Record 1
---------
KEY = 1
Name = Fred Boggs
Age = 84


Record 2
--------
KEY = 2
Name = Fred Boggs
Age = 84

这两个记录是不同的，因为字段KEY是不同的。
因此，尽管其余数据相同，但符合1NF的要求。

These 2 records are different because the field KEY is different. Therefore although the rest of the data is the same, it meets the requirements for 1NF.

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