在驗證數據庫邏輯模式到第三范式時需要一些幫助

Question

這最初是對另一個問題中提出的邏輯模式的“更新”： MySQL中出現ERROR 1701，ERROR 1452和ERROR 1305錯誤 - 需要一些專業知識 ......

我想我已成功將此模式驗證為第1和第2范式，但我不確定這是否符合第3范式。 這是有問題的模型：

這里是相關的代碼（注意：由於某種原因，我無法在sql代碼中重新創建1：1關系，如上面的邏輯模型所示）：

-- 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;

從以下鏈接：

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

這是我對3NF標准化的理解：

• 第一范式意味着不允許重復值
• 第二范式表示1NF，屬性依賴於整個主鍵而不是主鍵的一部分（如果該表中的值需要以某種方式相互關聯並進行比較，我認為這是分區表）。
• 第三范式表示2NF且沒有交易值（例如，如果x = y且y = z，x = z）

將這些知識從理論付諸實踐對我來說非常困難，特別是將“實踐”轉化為工作的，規范化的MySQL代碼。 如果有人能夠幫助我完成模型並給我一些關於將模型標准化為3NF的指示，我將非常感激。

提前致謝！

Answer 1

有一種算法可以最終分解模式中的每個關系，以便在3NF中獲得等效模式。 谷歌對此有好處！

要獲得有關架構設計的提示，您至少應該描述需要表示的實體的上下文和功能約束。

Answer 2

我認為這不是在3NF，在contact表周圍。 如果我錯了，這仍然是存儲數據的壞方法，應該可能會改變。

對不起，如果這有點困惑......

完全可以在contact表中具有以下結構，因為整個表是主鍵：

+----------+-------------+---------------+---------+
| 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都是重復的，因此更新表homephone將導致3次更新contact 。

我不同意數據模型，因為你需要一個person有一個我沒有的homehone ，只有一部手機。 在這種情況下，創建一個新的時person ，你也必須創建一個新的contact和新的homephone 。

由於contact僅僅是一個主鍵，主鍵的值不能為空，你還需要創建mobilephone和emailaddress ，這意味着person是依賴於emailaddress 。

由於emailaddress依賴於contact ，而contact依賴於person你創建了一個循環依賴，打破了3NF。

當我看到它，你有兩個選擇，如果你想保證人們一直到有一個家的電話號碼：

1. 如果您只想要一個person擁有一部 homephone那么將其添加到person表中。 它是唯一的聯系級別信息，應存儲在那里。
2. 如果你想使人們有多個家庭電話號碼-記住，多人可以使用同一個電話號碼-但不關心手機，那么你需要創建一個表personhomephones ，也就是說，與主鍵personid, homephoneid和沒有把homephoneid放在聯系表中。

就個人而言，我不會做其中任何一個。 我不會確保有人必須有一個家庭電話號碼，而是一個主要電話號碼，你不關心它是什么類型。 我會允許人們添加不同的聯系方式，但允許這些方法不存在

這需要以下結構：

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

然后，對於不存在的聯系方法：

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

雖然這可能導致contact和主要primaryphone之間的重復， primaryphone它們是不同的數據位，我認為這很好。 如果您堅持不允許任何重復，則必須將手機與其他聯系方式分開，這會使模型更加復雜：

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