在验证数据库逻辑模式到第三范式时需要一些帮助

时间：2012-04-22 04:02:17

标签： mysql sql database-design normalization third-normal-form

这最初是对另一个问题中提出的逻辑架构的“更新”：Getting ERROR 1701, ERROR 1452 and ERROR 1305 errors in MySQL - Need some expertise ...

我认为我已成功将此架构验证为第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：

An attempt on a logical database model to Third Normal Form

这是关联的代码（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：

这是我对3NF标准化的理解：

  • 第一范式表示不允许重复值
  • 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，我会非常感激。

提前致谢！

2 个答案:

答案 0 :(得分：1)

有一个algorithm最终会分解您的架构中的每个关系，以便在3NF中获得等效的架构。 Google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。

答案 1 :(得分：1)

我认为这不在3NF，围绕contact表。如果我错了，这仍然是一种存储数据的坏方法，应该可以改变。

对不起，如果这有点困惑......

在contact表中完全可以使用以下结构，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都重复，因此更新表格homephone将导致对contact的3次更新。

我不同意数据模型，因为您要求 person拥有homehone我没有，只有移动设备。在这种情况下，在创建新的person时，您还必须创建新的contact和新的homephone。

由于contact只是主键而主键值不能为空，您还要求创建mobilephone和emailaddress，这意味着person依赖于emailaddress。

由于emailaddress依赖于contact，而person依赖于person，因此您创建了循环依赖关系，从而打破了3NF。

如我所知，如果你想确保人们拥有拥有家庭电话号码，你有两个选择：

  1. 如果您只想让homephone拥有一个 person，请添加此项 进入personhomephones表。它是独特的联系级别信息和 应存放在那里。
  2. 如果您想让人们拥有多个家庭电话号码 - 记住多人可以使用相同的电话号码 - 但是 不关心手机然后你需要创建一个表 例如，personid, homephoneid使用主键homephoneid，而不是将person放入联系人表格中。

    3. 我个人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：

    • primaryPhoneID - 添加primaryphone ( primaryphoneID, phonenumber)
    • primaryphoneID - PK contactType ( contactTypeID, contactType )

    然后，对于不允许存在的联系方式：

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

    虽然这可能导致primaryphone和phonetype ( phoneTypeId, phoneType )之间的重复，但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：

    • phone ( phoneID, phoneTypeID, phonenumber)
    • phoneID, phoneTypeID - PK contactPhone ( personID, phoneTypeID, phoneID )
    • {{1}} - PK所有
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