我一直在使用MySQL来设计一个数据库,当将其编译为SQL代码并执行时,会产生两个错误。一个错误提示:变量“唯一检查”不能设置为“NULL”的值
,另一个错误提示:写入和更新时出现重复键
。我有一种感觉是我的外键导致了这个问题,但仍然无法解决这个问题。我在下方附上了查询代码。
SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0;
SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0;
SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='TRADITIONAL,ALLOW_INVALID_DATES';
-- -----------------------------------------------------
-- Schema mydb
-- -----------------------------------------------------
DROP SCHEMA IF EXISTS `mydb` ;
-- -----------------------------------------------------
-- Schema mydb
-- -----------------------------------------------------
CREATE SCHEMA IF NOT EXISTS `mydb` DEFAULT CHARACTER SET utf8 ;
USE `mydb` ;
-- -----------------------------------------------------
-- Table `mydb`.`User`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `mydb`.`User` ;
CREATE TABLE IF NOT EXISTS `mydb`.`User` (
`idUser` INT NOT NULL,
`first_name` VARCHAR(45) NULL,
`last_name` VARCHAR(45) NULL,
`username` VARCHAR(45) NULL,
`password` VARCHAR(45) NULL,
`company_pin` VARCHAR(45) NULL,
`student_pin` VARCHAR(45) NULL,
`isAdmin` TINYINT(1) NULL DEFAULT 0,
`isCandidate` TINYINT(1) NULL,
`isVoter` TINYINT(1) NULL,
`votes_left` INT NULL,
`votes_achieved` INT NULL,
PRIMARY KEY (`idUser`))
ENGINE = InnoDB;
-- -----------------------------------------------------
-- Table `mydb`.`Issue`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `mydb`.`Issue` ;
CREATE TABLE IF NOT EXISTS `mydb`.`Issue` (
`idIssue` INT NOT NULL,
`issueTitle` VARCHAR(45) NULL,
`issueDescription` VARCHAR(255) NULL,
`userID` INT NULL,
`isResolved` TINYINT(1) NULL DEFAULT 0,
`upVotes` INT NULL,
PRIMARY KEY (`idIssue`),
INDEX `FK_USERID_idx` (`userID` ASC),
CONSTRAINT `FK_USERID`
FOREIGN KEY (`userID`)
REFERENCES `mydb`.`User` (`idUser`)
ON DELETE CASCADE
ON UPDATE CASCADE)
ENGINE = InnoDB;
-- -----------------------------------------------------
-- Table `mydb`.`Forum`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `mydb`.`Forum` ;
CREATE TABLE IF NOT EXISTS `mydb`.`Forum` (
`idForum` INT NOT NULL,
`userID` INT NULL,
`postTitle` VARCHAR(45) NULL,
`postText` VARCHAR(255) NULL,
`upVotes` INT NULL,
PRIMARY KEY (`idForum`),
INDEX `FK_USERID_idx` (`userID` ASC),
CONSTRAINT `FK_USERID`
FOREIGN KEY (`userID`)
REFERENCES `mydb`.`User` (`idUser`)
ON DELETE CASCADE
ON UPDATE CASCADE)
ENGINE = InnoDB;
-- -----------------------------------------------------
-- Table `mydb`.`Vote`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `mydb`.`Vote` ;
CREATE TABLE IF NOT EXISTS `mydb`.`Vote` (
`idVote` INT NOT NULL,
`voteFor` ENUM('TOPIC', 'USER', 'ISSUE') NULL,
`topicID` INT NULL,
`userID` INT NULL,
`issueID` INT NULL,
PRIMARY KEY (`idVote`),
INDEX `FK_USER_VOTED_FOR_idx` (`userID` ASC),
INDEX `FK_ISSUE_VOTED_FOR_idx` (`issueID` ASC),
INDEX `FK_FORUM_VOTED_FOR_idx` (`topicID` ASC),
CONSTRAINT `FK_USER_VOTED_FOR`
FOREIGN KEY (`userID`)
REFERENCES `mydb`.`User` (`idUser`)
ON DELETE CASCADE
ON UPDATE CASCADE,
CONSTRAINT `FK_ISSUE_VOTED_FOR`
FOREIGN KEY (`issueID`)
REFERENCES `mydb`.`Issue` (`idIssue`)
ON DELETE CASCADE
ON UPDATE CASCADE,
CONSTRAINT `FK_FORUM_VOTED_FOR`
FOREIGN KEY (`topicID`)
REFERENCES `mydb`.`Forum` (`idForum`)
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
SET SQL_MODE=@OLD_SQL_MODE;
SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS;
SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS;