數據庫設計的3範式理解

原創 phpnewbie 2020-02-24 23:50

數據庫設計的範式

1。去除列上的一對多關係滿足第一範式

比如學生選課


學生名 課目名    該表不符合第一範式因爲一個學生對應了多個課目名


2。分離與主鍵沒有關係的字段到另外的表 滿足第二範式

比如下表

學生名 教室號 教室號和學生名沒有關係，因該分離該字段形成一個教室表


3。不是主鍵的字段不能有一對一的關係


 課目號  課目名 教師名 教師號


教師名和教師號有一對一關係，因該分離教師名和教師號

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