Question

DROP SCHEMA IF EXISTS `YouthMinistry` ;
CREATE SCHEMA IF NOT EXISTS `YouthMinistry` DEFAULT CHARACTER SET utf16 COLLATE utf16_general_ci ;
USE `YouthMinistry` ;

-- -----------------------------------------------------
-- Table `YouthMinistry`.`group`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `YouthMinistry`.`group` ;

CREATE TABLE IF NOT EXISTS `YouthMinistry`.`group` (
  `groupid` INT NOT NULL AUTO_INCREMENT ,
  `group_name` VARCHAR(100) NOT NULL ,
  `group_desc` VARCHAR(255) NULL ,
  PRIMARY KEY (`groupid`) )
ENGINE = InnoDB;


-- -----------------------------------------------------
-- Table `YouthMinistry`.`groupmembers`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `YouthMinistry`.`groupmembers` ;

CREATE TABLE IF NOT EXISTS `YouthMinistry`.`groupmembers` (
  `groupid` INT NOT NULL ,
  `memberid` INT NOT NULL ,
  PRIMARY KEY (`groupid`, `memberid`) ,
  INDEX `groupid_idx` (`groupid` ASC) ,
  CONSTRAINT `groupid`
    FOREIGN KEY (`groupid` )
    REFERENCES `YouthMinistry`.`group` (`groupid` )
    ON DELETE NO ACTION
    ON UPDATE NO ACTION)
ENGINE = InnoDB;


-- -----------------------------------------------------
-- Table `YouthMinistry`.`role`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `YouthMinistry`.`role` ;

CREATE TABLE IF NOT EXISTS `YouthMinistry`.`role` (
  `roleid` INT NOT NULL AUTO_INCREMENT ,
  `role_name` VARCHAR(100) NOT NULL ,
  `role_desc` VARCHAR(255) NULL ,
  PRIMARY KEY (`roleid`) )
ENGINE = InnoDB;


-- -----------------------------------------------------
-- Table `YouthMinistry`.`rolemembers`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `YouthMinistry`.`rolemembers` ;

CREATE TABLE IF NOT EXISTS `YouthMinistry`.`rolemembers` (
  `roleid` INT NOT NULL ,
  `memberid` INT NOT NULL ,
  PRIMARY KEY (`roleid`, `memberid`) ,
  INDEX `groupid_idx` (`roleid` ASC) ,
  FOREIGN KEY (`roleid` )
    REFERENCES `YouthMinistry`.`role` (`roleid` )
    ON DELETE NO ACTION
    ON UPDATE NO ACTION)
ENGINE = InnoDB;


-- -----------------------------------------------------
-- Table `YouthMinistry`.`users`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `YouthMinistry`.`users` ;

CREATE TABLE IF NOT EXISTS `YouthMinistry`.`users` (
  `memberid` INT NOT NULL AUTO_INCREMENT ,
  `username` VARCHAR(45) NOT NULL ,
  `password` VARCHAR(45) NOT NULL ,
  `email` VARCHAR(100) NULL ,
  `first_name` VARCHAR(45) NOT NULL ,
  `last_name` VARCHAR(45) NOT NULL ,
  `created` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `updated` DATETIME NOT NULL ,
  PRIMARY KEY (`memberid`, `username`, `password`) ,
  UNIQUE INDEX `username_UNIQUE` (`username` ASC) ,
  INDEX `memberid_idx` (`memberid` ASC) ,
  INDEX `memberid_idx1` (`memberid` ASC) ,
  FOREIGN KEY (`memberid` )
    REFERENCES `YouthMinistry`.`groupmembers` (`memberid` )
    ON DELETE CASCADE
    ON UPDATE CASCADE,
  FOREIGN KEY (`memberid` )
    REFERENCES `YouthMinistry`.`rolemembers` (`memberid` )
    ON DELETE CASCADE
    ON UPDATE CASCADE)
ENGINE = InnoDB;


-- -----------------------------------------------------
-- Table `YouthMinistry`.`eventgroup`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `YouthMinistry`.`eventgroup` ;

CREATE TABLE IF NOT EXISTS `YouthMinistry`.`eventgroup` (
  `eventid` INT NOT NULL ,
  `groupid` VARCHAR(45) NOT NULL ,
  PRIMARY KEY (`eventid`, `groupid`) ,
  INDEX `groupid_idx` (`groupid` ASC) ,
  FOREIGN KEY (`groupid`)
    REFERENCES `YouthMinistry`.`group` (`groupid`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION)
ENGINE = InnoDB;


-- -----------------------------------------------------
-- Table `YouthMinistry`.`event`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `YouthMinistry`.`event` ;

CREATE TABLE IF NOT EXISTS `YouthMinistry`.`event` (
  `eventid` INT NOT NULL AUTO_INCREMENT ,
  `event_name` VARCHAR(255) NOT NULL ,
  `event_desc` VARCHAR(255) NULL ,
  PRIMARY KEY (`eventid`) ,
  INDEX `eventid_idx` (`eventid` ASC) ,
  FOREIGN KEY (`eventid` )
    REFERENCES `YouthMinistry`.`eventgroup` (`eventid` )
    ON DELETE CASCADE
    ON UPDATE CASCADE)
ENGINE = InnoDB;

我正在为我正在制作的网站创建数据库，当我运行创建脚本时，它会给我以下错误：错误代码：1005。无法创建表'youthministry.users'（错误号：150）

我查看了以下来源，了解此错误的可能解决方案： http://www.webdeveloper.com/forum/showthread.php?68260-mySQL-multiple-foreign-keys http://forums.devarticles.com/mysql-development-50/mysql-foreign-key-problem-errno-150t-7704.html

我已经检查了主键和外键声明，以确保一切正确。

非常感谢任何帮助。此外，这仍然是一个原型，欢迎任何关于初始架构的评论。我还是数据库设计的新手。

Answer 1

您只能在一个引用另一个表上的键的表上创建外键。这个特定问题是memberid不是groupmembers或rolemembers表的关键。只需将KEY (memberid)添加到这些表中，您就可以了。

另外一个问题是外键类型必须匹配。 eventgroup有groupid varchar，但正在引用groups表，其中包含groupid INT。纠正这个。

至于建议，我强烈建议每个主键只有一列：自动增量代理键。你也应该使这些无符号整数。

MySql错误：＃105（代码150）。当我创建数据库模式时，我收到错误代码150。

1 个答案: