MySql错误:#105(代码150).当我创建数据库模式时，我收到一个错误代码150

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一个数据库，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(

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

我检查了主键和外键声明，只是为了确保一切都是正确的。

非常感谢您的帮助。此外，这仍然是一个原型，欢迎对初始模式发表任何评论。我还是数据库设计的新手。

Answer 1

您只能在一个表上创建一个外键，该外键引用另一个表的键。这个特定的问题是memberid不是groupmembers或rolemembers表上的键。只需将KEY (memberid)添加到这些表中，就可以使用了。

另一个问题是外键类型必须匹配。eventgroup具有groupid varchar，但正在引用具有groupid INT的groups表。纠正这个问题。

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至于建议，我强烈建议每个主键只有一列：您的自动递增代理键。你也应该做这些无符号整数。