mysql - 错误 1452 : Cannot add or update a child row

Question

我遇到了一个奇怪的问题，我正在尝试将外键添加到一个引用另一个表的表中，但由于某种原因它失败了。由于我对 MySQL 的了解有限，唯一可能怀疑的是在引用我试图引用的表的不同表上有一个外键。

这是我的表关系的图片，通过工作台生成:Relationships

CREATE TABLE `beds` (
  `bedId` int(11) NOT NULL,
  `wardId` int(11) DEFAULT NULL,
  `depId` int(11) DEFAULT NULL,
  `desc` varchar(45) DEFAULT NULL,
  PRIMARY KEY (`bedId`),
  KEY `departmentId_idx` (`depId`),
  KEY `wardId_idx` (`wardId`),
  CONSTRAINT `departmentId` FOREIGN KEY (`depId`) 
     REFERENCES `department` (`Department_Id`) 
     ON DELETE NO ACTION ON UPDATE NO ACTION,
  CONSTRAINT `wardId` FOREIGN KEY (`wardId`) REFERENCES `wards` (`wardId`) 
     ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB DEFAULT CHARSET=latin1$$

---

ERROR 1452: Cannot add or update a child row: a foreign key constraint fails
(`asiahospitaldb`.`beds`, CONSTRAINT `departmentId` FOREIGN KEY (`depId`) 
REFERENCES `department` (`Department_Id`) 
ON DELETE NO ACTION ON UPDATE NO ACTION)

SQL Statement:

INSERT INTO `asiahospitaldb`.`Beds` (`bedId`, `wardId`, `depId`, `desc`) 
VALUES ('456', '7444', '4555', 'ikiuj')

---

Answer 1

这个

ERROR 1452: Cannot add or update a child row: a foreign key constraint
fails (`asiahospitaldb`.`beds`, CONSTRAINT `departmentId` FOREIGN KEY
(`depId`)  REFERENCES `department` (`Department_Id`)  ON DELETE NO
`enter code here`ACTION ON UPDATE NO ACTION)

告诉您，您插入的行需要 department/department_id 对应于您插入列 depId 中的值(正如 Omesh 指出的那样)。重要的一点在这里:

(depId) REFERENCES department (Department_Id)

换句话说，您试图在一个不存在的部门中创建一张床。