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数据库规范化的第一种形式？

[英]First form of database normalization?

原文 2018-07-08 09:22:15 0 1 sql-server/ database

I have an ER diagram that I want normalize. 我有一个要标准化的ER图。 But I'm not sure if I normalize it correctly. 但是我不确定是否正确地对其进行了规范化。 Do I need to include every primary key to table the columns? 我是否需要包括每个主键才能列出这些列？

And here is my SQL Server code for my table. 这是我的表的SQL Server代码。 I'm not sure if this correct: http://rextester.com/BCA95581 我不确定是否正确： http ： //rextester.com/BCA95581

1 个解决方案

According to Wikipedia , a relation (table) is in first normal form: 根据Wikipedia所述，关系（表）的格式为第一种形式：

First normal form (1NF) is a property of a relation in a relational database. 第一范式（1NF）是关系数据库中关系的属性。 A relation is in first normal form if and only if the domain of each attribute contains only atomic (indivisible) values, and the value of each attribute contains only a single value from that domain. 当且仅当每个属性的域仅包含原子（不可分割）值且每个属性的值仅包含该域中的单个值时，关系才采用第一范式。 The first definition of the term, in a 1971 conference paper by Edgar Codd, defined a relation to be in first normal form when none of its domains have any sets as elements. 1971年，埃德加·科德（Edgar Codd）的会议论文中对该术语的第一个定义是，当一个关系的任何域都没有任何集合作为元素时，该关系应为第一范式。

So just the raw structure as you show it in the ER diagram doesn't really suffice to know if the tables are in 1NF - it depends on the domain and the possible data types. 因此，仅显示在ER图中的原始结构实际上不足以知道这些表是否位于1NF中-它取决于域和可能的数据类型。 Just make sure that 只要确保

(1) each attribute (column in every table) can only hold atomic values (no arrays, lists, objects, comma-separated values etc.) （1）每个属性（每个表中的列）只能保存原子值 （没有数组，列表，对象，逗号分隔的值等）

(2) no column can ever hold more than 1 of these values （2）没有列可以容纳超过1个这些值

If you're using the basic data types of SQL Server, then you should be fine. 如果您使用的是SQL Server的基本数据类型，那应该没问题。