在验证数据库逻辑模式到第三范式时需要一些帮助

Question

这最初是对另一个问题中提出的逻辑模式的“更新”： MySQL中出现ERROR 1701，ERROR 1452和ERROR 1305错误 - 需要一些专业知识 ......

我想我已成功将此模式验证为第1和第2范式，但我不确定这是否符合第3范式。 这是有问题的模型：

这里是相关的代码（注意：由于某种原因，我无法在sql代码中重新创建1：1关系，如上面的逻辑模型所示）：

-- 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;

从以下链接：

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

这是我对3NF标准化的理解：

• 第一范式意味着不允许重复值
• 第二范式表示1NF，属性依赖于整个主键而不是主键的一部分（如果该表中的值需要以某种方式相互关联并进行比较，我认为这是分区表）。
• 第三范式表示2NF且没有交易值（例如，如果x = y且y = z，x = z）

将这些知识从理论付诸实践对我来说非常困难，特别是将“实践”转化为工作的，规范化的MySQL代码。 如果有人能够帮助我完成模型并给我一些关于将模型标准化为3NF的指示，我将非常感激。

提前致谢！

Answer 1

有一种算法可以最终分解模式中的每个关系，以便在3NF中获得等效模式。 谷歌对此有好处！

要获得有关架构设计的提示，您至少应该描述需要表示的实体的上下文和功能约束。

Answer 2

我认为这不是在3NF，在contact表周围。 如果我错了，这仍然是存储数据的坏方法，应该可能会改变。

对不起，如果这有点困惑......

完全可以在contact表中具有以下结构，因为整个表是主键：

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

正如您所看到的， homephoneid和mobilephoneid都是重复的，因此更新表homephone将导致3次更新contact 。

我不同意数据模型，因为你需要一个person有一个我没有的homehone ，只有一部手机。 在这种情况下，创建一个新的时person ，你也必须创建一个新的contact和新的homephone 。

由于contact仅仅是一个主键，主键的值不能为空，你还需要创建mobilephone和emailaddress ，这意味着person是依赖于emailaddress 。

由于emailaddress依赖于contact ，而contact依赖于person你创建了一个循环依赖，打破了3NF。

当我看到它，你有两个选择，如果你想保证人们一直到有一个家的电话号码：

1. 如果您只想要一个person拥有一部 homephone那么将其添加到person表中。 它是唯一的联系级别信息，应存储在那里。
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 ，也就是说，与主键personid, homephoneid和没有把homephoneid放在联系表中。

就个人而言，我不会做其中任何一个。 我不会确保有人必须有一个家庭电话号码，而是一个主要电话号码，你不关心它是什么类型。 我会允许人们添加不同的联系方式，但允许这些方法不存在

这需要以下结构：

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

然后，对于不存在的联系方法：

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

虽然这可能导致contact和主要primaryphone之间的重复， primaryphone它们是不同的数据位，我认为这很好。 如果您坚持不允许任何重复，则必须将手机与其他联系方式分开，这会使模型更加复杂：

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