需要验证数据库逻辑模式，以第三范式

Question

一些援助，这原本会是一个“更新”在这里另外一个问题提出的逻辑模式：Getting ERROR 1701, ERROR 1452 and ERROR 1305 errors in MySQL - Need some expertise ...

我想我已经成功验证这种模式到第一和第二范式，但我不确定这是否符合第三范式。这是有问题的模式：

这里是相关的代码（注：由于某种原因，我无法重新创建1：在逻辑模型说明在上面的SQL代码1间的关系）：

-- database_schema.sql. 
-- This sql script creates the structure. 
-- of the rugby club database. 

DROP DATABASE IF EXISTS database_rugby; 

CREATE DATABASE database_rugby; 

USE database_rugby; 

-- Create the "person" table. 
-- 
-- This table has one:one relationships 
-- with the parent, coach and player 
-- tables. 
DROP TABLE IF EXISTS `person` ; 
CREATE TABLE `person` (
    `personID` INT(5) NOT NULL AUTO_INCREMENT , 
    `firstName` VARCHAR(50) NOT NULL , 
    `lastName` VARCHAR(50) NOT NULL , 
    `dateOfBirth` DATE NOT NULL , 
    `streetAddress` VARCHAR(150) NOT NULL , 
    `suburbAddress` VARCHAR(150) NULL DEFAULT NULL , 
    `cityAddress` VARCHAR(150) NOT NULL , 
    `photo` BLOB NULL DEFAULT NULL , 
    PRIMARY KEY (`personID`)) 
ENGINE = InnoDB; 

-- Create the "parent" table. 
DROP TABLE IF EXISTS `parent` ; 
CREATE TABLE `parent` (
    `parentID` INT(5) NOT NULL , 
    `personID` INT(5) NOT NULL , 
    PRIMARY KEY (`parentID`, `personID`), 
    FOREIGN KEY (`personID`) REFERENCES `person` (`personID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE) 
ENGINE = InnoDB; 


-- Create the "school" table. 
DROP TABLE IF EXISTS `school` ; 
CREATE TABLE `school` (
    `schoolID` INT(5) NOT NULL AUTO_INCREMENT , 
    `schoolName` VARCHAR(100) NOT NULL , 
    PRIMARY KEY (`schoolID`)) 
ENGINE = InnoDB; 


-- Create the "player" table. 
-- 
-- Inherits fields from the "person" 
-- and "school" tables. 
DROP TABLE IF EXISTS `player` ; 

CREATE TABLE `player` (
    `playerID` INT(5) NOT NULL , 
    `personID` INT(5) NOT NULL , 
    `schoolID` INT(5) NOT NULL , 
    PRIMARY KEY (`playerID`, `personID`), 
    FOREIGN KEY (`personID`) 
    REFERENCES `person` (`personID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE, 
    FOREIGN KEY (`schoolID`) 
    REFERENCES `school` (`schoolID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE) 
ENGINE = InnoDB; 


-- Create the "coach" table. 
DROP TABLE IF EXISTS `coach`; 
CREATE TABLE `coach`(
    `coachID` INT(5) NOT NULL , 
    `dateBeganCoaching` DATE NOT NULL , 
    `personID` INT(5) NOT NULL , 
    PRIMARY KEY (`coachID`, `personID`), 
    FOREIGN KEY (`personID`) 
    REFERENCES `person` (`personID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE) 
ENGINE = InnoDB; 


-- Create the "family" table. 
-- 
-- This is a linking table 
-- that describes the many:many 
-- relationship between "parent" 
-- and "player" tables. 
DROP TABLE IF EXISTS `family` ; 
CREATE TABLE `family` (
    `parentID` INT(5) NOT NULL , 
    `playerID` INT(5) NOT NULL , 
    FOREIGN KEY (`playerID`) 
    REFERENCES `player` (`playerID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE, 
    FOREIGN KEY (`parentID`) 
    REFERENCES `parent` (`parentID`) 
    ON DELETE NO ACTION 
    ON UPDATE NO ACTION) 
ENGINE = InnoDB; 


-- Create the "grade" table. 
DROP TABLE IF EXISTS `grade`; 
CREATE TABLE `grade`(
    `gradeID` INT(5) NOT NULL AUTO_INCREMENT , 
    `gradeName` VARCHAR(50) NOT NULL , 
    `minWeight` INT(3) NOT NULL , 
    `maxWeight` INT(3) NOT NULL , 
    `minAge` INT(3) NOT NULL , 
    `maxAge` INT(3) NOT NULL , 
    `ballSize` INT(1) NOT NULL , 
    PRIMARY KEY (`gradeID`)) 
ENGINE = InnoDB; 


-- Create the "coachQualification" table. 
DROP TABLE IF EXISTS `coachQualification` ; 

CREATE TABLE `coachQualification` (
    `qualID` INT(5) NOT NULL AUTO_INCREMENT , 
    `qualName` CHAR(5) NOT NULL , 
    `gradeID` INT(5) NOT NULL , 
    PRIMARY KEY (`qualID`) , 
    FOREIGN KEY (`gradeID`) 
    REFERENCES `grade` (`gradeID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE) 
ENGINE = InnoDB; 


-- Create the "homePhone" table. 
DROP TABLE IF EXISTS `homePhone` ; 
CREATE TABLE `homePhone` (
    `homePhoneID` INT(5) NOT NULL AUTO_INCREMENT , 
    `homeNumber` CHAR(9) NOT NULL , 
    PRIMARY KEY (`homePhoneID`)) 
ENGINE = InnoDB; 


-- Create the "mobilePhone" table. 
DROP TABLE IF EXISTS `mobilePhone` ; 

CREATE TABLE `mobilePhone` (
    `mobilePhoneID` INT(5) NOT NULL AUTO_INCREMENT , 
    `mobileNumber` CHAR(10) NULL DEFAULT NULL , 
    PRIMARY KEY (`mobilePhoneID`)) 
ENGINE = InnoDB; 


-- Create the "emailAddress" table. 
DROP TABLE IF EXISTS `emailAddress` ; 

CREATE TABLE `emailAddress` (
    `emailAddressID` INT(5) NOT NULL AUTO_INCREMENT , 
    `emailAddress` CHAR(10) NULL DEFAULT NULL , 
    PRIMARY KEY (`emailAddressID`)) 
ENGINE = InnoDB; 


-- Create the "Contact" table 
-- 
-- This is a linking table 
-- that describes the many:many 
-- relationships between "person" 
-- and the "homePhone", "mobilePhone", 
-- and "emailAddress" tables. 
DROP TABLE IF EXISTS `contact` ; 
CREATE TABLE `contact` (
    `personID` INT(5) NOT NULL , 
    `homePhoneID` INT(5) NOT NULL , 
    `mobilePhoneID` INT(5) NULL DEFAULT NULL , 
    `emailAddressID` INT(5) NULL DEFAULT NULL , 
    FOREIGN KEY (`personID`) 
    REFERENCES `person` (`personID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE, 
    FOREIGN KEY (`homePhoneID`) 
    REFERENCES `homePhone` (`homePhoneID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE, 
    FOREIGN KEY (`mobilePhoneID`) 
    REFERENCES `mobilePhone` (`mobilePhoneID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE, 
    FOREIGN KEY (`emailAddressID`) 
    REFERENCES `emailAddress` (`emailAddressID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE) 
ENGINE = InnoDB; 


-- Create the "qualificationSet" table. 
-- 
-- This is a linking table 
-- that describes the many:many 
-- relationship between "coach" 
-- and "coachQualification" tables. 
DROP TABLE IF EXISTS `qualificationSet` ; 
CREATE TABLE `qualificationSet` (
    `coachID` INT(5) NOT NULL , 
    `qualID` INT(5) NOT NULL , 
    FOREIGN KEY (`coachID`) 
    REFERENCES `coach` (`coachID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE, 
    FOREIGN KEY (`qualID`) 
    REFERENCES `coachQualification` (`qualID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE) 
ENGINE = InnoDB; 


-- Create the "team" table. 
DROP TABLE IF EXISTS `team` ; 
CREATE TABLE `team` (
    `teamID` INT(5) NOT NULL AUTO_INCREMENT , 
    `teamName` VARCHAR(50) NOT NULL , 
    `teamYear` INT(2) NOT NULL , 
    `gradeID` INT(5) NOT NULL , 
    PRIMARY KEY (`teamID`) , 
    FOREIGN KEY (`gradeID`) 
    REFERENCES `grade` (`gradeID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE) 
ENGINE = InnoDB; 


-- Create the "teamAllocation" table 
-- 
-- this is a linking table for a 
-- many:many relationship between 
-- team and player tables. 
DROP TABLE IF EXISTS `teamAllocation` ; 

CREATE TABLE `teamAllocation` (
    `teamID` INT(5) NOT NULL , 
    `playerID` INT(5) NOT NULL , 
    FOREIGN KEY (`teamID`) 
    REFERENCES `team` (`teamID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE, 
    FOREIGN KEY (`playerID`) 
    REFERENCES `player` (`playerID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE) 
ENGINE = InnoDB; 


-- Create the "teamCoachAllocation" table. 
-- 
-- This is a linking table 
-- that describes the many:many 
-- relationship between "coach" 
-- and "team" tables. 
DROP TABLE IF EXISTS `teamCoachAllocation` ; 
CREATE TABLE `teamCoachAllocation` (
    `coachID` INT(5) NOT NULL , 
    `teamID` INT(5) NOT NULL , 
    FOREIGN KEY (`coachID`) 
    REFERENCES `coach` (`coachID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE, 
    FOREIGN KEY (`teamID`) 
    REFERENCES `team` (`teamID`) 
    ON DELETE CASCADE 
    ON UPDATE CASCADE) 
ENGINE = InnoDB; 

从下面这些链接：

• http://en.wikipedia.org/wiki/First_normal_form
• http://en.wikipedia.org/wiki/Second_normal_form
• http://en.wikipedia.org/wiki/Third_normal_form

这是我的规范化的理解到3NF：

• 首先正常形式意味着不允许重复值
• 第二范式装置1NF和属性是依赖于整个主键而不是主键的一部分（我认为这是分区表，如果表中的值需要以某种方式与彼此相关并进行比较）。
• 第三范式是指2NF，没有1晶体管值（例如，如果X = Y和Y = Z，X = Z）

把知识从理论到实践是非常难受，尤其是翻译的是“练习“到正常工作的MySQL代码中。如果有人能够帮助我浏览模型并给我一些关于将模型归一化为3NF的指导，我将非常感激。

在此先感谢！

Answer 1

我认为这不是在3NF，围绕着contact表。如果我错了，这仍然是一种存储数据的不好方法，应该可能改变。

很抱歉，如果这是一个有点糊涂了......

这是完全有可能具有以下结构在contact表作为整个表的主键：

 
+----------+-------------+---------------+---------+ 
| personid | homephoneid | mobilephoneid | emailid | 
+----------+-------------+---------------+---------+ 
|  1 |   1 |    1 |  1 | 
|  1 |   1 |    1 |  2 | 
|  1 |   1 |    2 |  3 | 
+----------+-------------+---------------+---------+ 

，你可以见homephoneid和mobilephoneid都是重复的，所以更新表homephone将导致3更新为contact。

我与数据模型不同意，你需要一个person有homehone我没有一个，只有一个移动。在这种情况下，创建新的person时，还必须创建新的contact和新的homephone。

由于contact仅仅是一个主键，主键的值不能为空，也需要创建一个mobilephone和emailaddress的，这意味着person取决于emailaddress。

由于emailaddress依赖于contact，依次取决于person您创建了一个循环依赖关系，它打破3NF。

当我看到它，你有两个选择，如果你想确保人们有有一个家庭电话号码：

1. 如果你只想要一个person有一个homephone再加入这 到person表。这是唯一的联系级别信息，并且 应该存储在那里。
2. 如果你想使人们有多个家庭电话号码 - 记住，多人可以使用同一个电话号码 - 但 不关心手机，那么你需要创建一个表 personhomephones，比方说，与主键personid, homephoneid，而不是将homephoneid放在联系人表中。

就我个人而言，我不会这样做。我不能确保有人必须有一个家庭电话号码，而是一个主要的电话号码，你不关心它是什么类型。我可以让人们将联系人添加不同的方法，但允许这些不存在

这需要以下结构：

• person - 添加primaryPhoneID
• primaryphone (primaryphoneID, phonenumber) - PK primaryphoneID

然后对于允许不存在的联系方式：

• contactType (contactTypeID, contactType) - PK contactTypeID
• contact (contactID, contactTypeID, value) - PK contactID, contactTypeID
• personContact (personID, contactID, contactTypeID) - PK一切

虽然这可能会导致重复contact和primaryphone他们的数据不同的位，我认为这是好的之间。如果您对不允许在所有任何重复是坚持你必须从接触的其他方法，使模型更加复杂，分离出的手机：

• phonetype (phoneTypeId, phoneType)
• phone (phoneID, phoneTypeID, phonenumber) - PK phoneID, phoneTypeID
• contactPhone (personID, phoneTypeID, phoneID) - PK一切

Answer 2

有一个algorithm最终分解您的架构中的每个关系，以获得3NF中的等效架构。 Google很好！

要获得关于您的模式设计的提示，您至少应该描述关于您需要表示的实体的上下文和功能约束。