这些规范化形式以及如何转换为3NF [英] Which normalization form are these and how to convert to 3NF

问题描述

1。假设：student_id是主键。学生可以拥有多个电话号码，但只有一个专业。每个宿舍有一个RA; 'dorm'是学生宿舍的名称，是独一无二的。



学生（student_id，宿舍，电话，专业，RA）







2.假设：student_id是主键。学生只能有一名顾问。您可以假设顾问程序名称是唯一标识符。每个顾问只与一个部门相关联。







学生（student_id，advisor_name，advisor_dept）< br $> b $ b





3.假设存在这些依赖关系：



类型 - >价格



作者 - > author_affiliation



书（作者，职称，类型，价格，出版商，author_affiliation）



我尝试了什么：



我很难确定它们是哪种正常形式。

和转换为3nf的过程

1. Assumptions: The student_id is the primary key. Students can have more than one phone number but only one major. There is one RA per dorm; ‘dorm’ is the name of the student’s dormatory and is unique.

Student (student_id, dorm, phone, major, RA)



2. Assumptions: The student_id is the primary key. Students can have only one advisor. You may assume the advisor names are a unique identifier. Each advisor is associated with exactly one department.



Student (student_id, advisor_name, advisor_dept)



3. Assume these dependencies exist:

type --> price

author --> author_affiliation

Book (author, title, type, price, publisher, author_affiliation)

What I have tried:

I am struggling to indentify which normal form are they.
and process in converting to 3nf

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请遵循以下提示：

假设1：

Follow these hints:
Assumption 1:

提示1：

学生可以拥有多个电话号码;每个宿舍有一个RA。

Students can have more than one phone numbers; and there is one RA per dorm.

假设2：

Assumption 2:

提示2：

其中一个字段（属性）与学生实体无关，换句话说，它在学生表中没有位置

One of the fields (attributes) has no relation to the student entity, in other words, it has no place in student table

假设3：

Assumption 3:

提示3：

与提示2类似。

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