To better understand the definition for first normal form, it helps to know the difference between a domain, an attribute, and a column. Adomainis the set of all possible values for a particular type of attribute, but may be used for more than one attribute. For example, the domain of ...
First normal form (1NF) sets the fundamental rules for database normalization and relates to a single table within a relational database system. Normalization follows three basic steps, each building on the last. The first of these is the first normal form. The first normal form states that: ...
第一范式(1NF)主要关注数据的结构,特别是表中的列。为达到1NF,数据库中每一个列必须只保存一个单一的值,而不能是集合或重复项。这一要求意味着,如果有一个列包含多个值,例如一名学生的多科成绩,则这个设计并不符合第一范式的标准。为了将此类数据转换为符合1NF的形式,我们需要拆分这些数据,将表中的条目进行适当...
First normal form (1NF) 相关知识点: 试题来源: 解析 第一范式(1NF)要求数据库表的每一列都是原子性的,即不可再分,且每一行都是唯一的。 第一范式(1NF)是数据库规范化的基础规则。其核心要求是:1. **原子性**:表中的每一列必须包含不可再分的单一值,不能有集合、数组或嵌套结构。例如,“电话”字段...
7.3 First Normal Form (1NF) (11:15) 是在优酷播出的教育高清视频,于2015-10-22 14:14:12上线。视频内容简介:ShareCourse-CS13001 資料庫系統 Database Systems
英语缩写词 "1NF"，通常代表 "First Normal Form"，中文直译为“第一范式”。这个术语在数据库理论中至关重要，它用于描述数据模型的组织原则，确保数据的一致性和准确性。1NF是数据模型规范化的第一步，它要求数据表中的每个列应包含原子值，即不能再进一步分解的最小单位。1NF在学术界特别是数学领域...
Now that we understand the steps to transform a table and achieve 1NF, let’s have a look at two practical first normal form examples. Example 1: Customer orders table Imagine aCustomer Orderstable that looks like this: CustomerIDNameProduct1Product2OrderDate ...
The first level of guidelines for designing table and data structures in a relational database. The first normal form guideline recommends creating a unique key for every row in a database table, elim
10- 第一范式 | 1NF- First Normal Form 2387 播放 硬核科技 最全硬核科技干货>> 收藏 下载 分享 手机看 选集(155) 自动播放 [1] (中字)【第一章】1- 介绍 | ... 8.5万播放 00:18 [2] (中字)2- 什么是SQL | W... 6.0万播放 03:24 ...
1NF First Normal Form Further, various technical terms are used throughout this description. A definition of such terms can be found inNewton's Telecom Dictionaryby H. Newton, 22ndEdition (2006). These definitions are intended to provide a clearer understanding of the ideas disclosed herein but ...