客户表将不允许约束

Question

嘿，所以我正在尝试加载我的数据库。我得到的错误是

CREATE TABLE `customers` (
  `customerNumber` int(11) NOT NULL,
  `customerName` varchar(50) NOT NULL,
  `contactLastName` varchar(50) NOT NULL,
  `contactFirstName` varchar(50) NOT NULL,
  `phone` varchar(50) NOT NULL,
  `addressLine1` varchar(50) NOT NULL,
  `addressLine2` varchar(50) DEFAULT NULL,
  `city` varchar(50) NOT NULL,
  `state` varchar(50) DEFAULT NULL,
  `postalCode` varchar(15) DEFAULT NULL,
  `country` varchar(50) NOT NULL,
  `salesRepEmployeeNumber` int(11) DEFAULT NULL,
  `creditLimit` decimal(10,2) DEFAULT NULL,
  PRIMARY KEY (`customerNumber`),
  KEY `salesRepEmployeeNumber` (`salesRepEmployeeNumber`),
  CONSTRAINT `customers_ibfk_1` FOREIGN KEY (`salesRepEmployeeNumber`) REFERENCES `employees` (`employeeNumber`)

) ENGINE=InnoDB DEFAULT CHARSET=latin1

MySQL说：文档

1215-无法添加外键约束

我理解错误，但是约束带来了什么问题？

编辑：

0

CREATE TABLE `employees` (
  `employeeNumber` int(11) NOT NULL,
  `lastName` varchar(50) NOT NULL,
  `firstName` varchar(50) NOT NULL,
  `extension` varchar(10) NOT NULL,
  `email` varchar(100) NOT NULL,
  `officeCode` varchar(10) NOT NULL,
  `reportsTo` int(11) DEFAULT NULL,
  `jobTitle` varchar(50) NOT NULL,
  PRIMARY KEY (`employeeNumber`),
  KEY `reportsTo` (`reportsTo`),
  KEY `officeCode` (`officeCode`),
  CONSTRAINT `employees_ibfk_1` FOREIGN KEY (`reportsTo`) REFERENCES `employees` (`employeeNumber`),
  CONSTRAINT `employees_ibfk_2` FOREIGN KEY (`officeCode`) REFERENCES `offices` (`officeCode`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

CREATE TABLE `offices` (
  `officeCode` varchar(10) NOT NULL,
  `city` varchar(50) NOT NULL,
  `phone` varchar(50) NOT NULL,
  `addressLine1` varchar(50) NOT NULL,
  `addressLine2` varchar(50) DEFAULT NULL,
  `state` varchar(50) DEFAULT NULL,
  `country` varchar(50) NOT NULL,
  `postalCode` varchar(15) NOT NULL,
  `territory` varchar(10) NOT NULL,
  PRIMARY KEY (`officeCode`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

Answer 1

好的，您应该按以下顺序创建表：

> toList (Node 'x' (Leaf 1.0) (Node 'y' (Leaf 3.0) (Leaf 4.0)))
([1.0,3.0,4.0],"xy")
> toList' (Node 'x' (Leaf 1.0) (Node 'y' (Leaf 3.0) (Leaf 4.0)))
([1.0,3.0,4.0],"xy")
>

问题是您试图首先创建表客户，并且它引用的表（员工）不存在。