Question

我正在进行数据库作业，我遇到了几个部分的问题。我的数据库架构是这样的：

CREATE TABLE `Movies` (
  `title` varchar(255) NOT NULL,
  `year` int(11) NOT NULL (CHECK year > 1928),
  `length` int(11) DEFAULT NULL (CHECK Length > 30 and Length < 280),
  `genre` varchar(255) DEFAULT NULL (CHECK genre = “Drama” or genre = “comedy” or genre = “sciFi” or genre =”romance” or genre = “vampire”,
  `academy_award` varchar(255) DEFAULT NULL,
  `studioName` varchar(255) DEFAULT NULL,
  `directorName` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`title`,`year`),
  KEY `studioName` (`studioName`),
  KEY `directorName` (`directorName`),
  CONSTRAINT `Movies_ibfk_2` FOREIGN KEY (`directorName`) REFERENCES `Director` (`name`) ON DELETE CASCADE ON UPDATE CASCADE,
  CONSTRAINT `Movies_ibfk_1` FOREIGN KEY (`studioName`) REFERENCES `Studio` (`name`) ON DELETE CASCADE ON UPDATE CASCADE
) 

CREATE TABLE `StarsIn` (
  `movieTitle` varchar(255) NOT NULL,
  `movieYear` int(11) NOT NULL,
  `starName` varchar(255) NOT NULL,
  PRIMARY KEY (`movieTitle`,`movieYear`,`starName`),
  KEY `starName` (`starName`),
  CONSTRAINT `StarsIn_ibfk_2` FOREIGN KEY (`starName`) REFERENCES `MovieStar` (`name`),
  CONSTRAINT `StarsIn_ibfk_1` FOREIGN KEY (`movieTitle`) REFERENCES `Movies` (`title`)
  CONSTRAINT `StarsIn_ibfk_2` FOREIGN KEY (`movieYear`) REFERENCES `Movies` (`year),

) 

CREATE TABLE `Director` (
  `name` varchar(255) NOT NULL,
  `birthday` date DEFAULT NULL,
  `nationality` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`name`)
)

CREATE TABLE `MovieStar` (
  `name` varchar(255) NOT NULL,
  `birthdate` date DEFAULT NULL,
  `address` varchar(255) DEFAULT NULL,
  `gender` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`name`)
)

CREATE TABLE `Studio` (
  `name` varchar(255) NOT NULL,
  `address` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`name`),
  UNIQUE KEY `address` (`address`)
)

我必须添加更多约束：

明星可能不会出现在他们出生前制作的电影中
Studio中显示的工作室名称也必须至少出现在一个电影元组

在浏览MySQL约束文档后，我不确定如何完成此操作。任何帮助将不胜感激。

检查有关数据库关系的约束

0 个答案: