mysql - 将数据库设置为 1NF 或 2NF - mysql

Question

如何以更好的 1NF 或 2NF 形式获取此 mysql 数据库？

我已尽力删除冗余数据。看来“Prof_Dept”中仍然存在冗余数据

Answer 1

架构看起来很奇怪。 Professor_Dept 的子级(其中包含 Professor_DeptID FK)如何创建部门？这意味着没有“科学学院”。您将存储

professor john's science department
professor john's physics department
professor tom's physics department
etc

我认为表格应该是

Professor
Department
   <bridge between the two> (Professor_Dept)
Course
   (this hangs off the bridge table, since the combination
    defines the Course instructor [professor] and department)

<小时/>

Professor: id, name, e.g. "John"
Department: id, name, e.g. "COM"
Professor_Dept: id, professor_id (FK), department_id (FK), modified_date
Course: Professor_Dept_id (FK), number, course_modified

从一门类(class)中，您已经通过 FK 知道它与哪位教授和部门相关。