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我正在尝试做的事情我已经做了无数次,但现在从 MySql 5.6.26 升级到 5.6.27 失败了(在 5.7.x 中也失败了)。我有一个数据库,其中包含一堆具有外键约束的表。我已导出(使用 phpMyAdmin)替换表,指定了以下导出选项:

Disable foreign key checks
Add DROP TABLE / VIEW / PROCEDURE / FUNCTION / EVENT / TRIGGER statement
Add CREATE TABLE statement

生成的导出文件部分包含:

SET FOREIGN_KEY_CHECKS=0;

DROP TABLE IF EXISTS `application`;
CREATE TABLE `application` (
  `PK_Application` int(11) NOT NULL,
  `FK_Parent` int(11) DEFAULT NULL,
  `ApplicationLevel` tinyint(4) NOT NULL,
  `Description` varchar(35) NOT NULL,
  `Sequence` tinyint(4) NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=15 DEFAULT CHARSET=latin1;

. . .
. . .

DROP TABLE IF EXISTS `product_x_application`;
CREATE TABLE `product_x_application` (
  `PK_Product_X_Application` int(11) NOT NULL,
  `Product_PKID` varchar(36) NOT NULL,
  `FK_Application` int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

. . .
. . .

ALTER TABLE `product_x_application`
  ADD CONSTRAINT `product_x_application_ibfk_2` FOREIGN KEY (`FK_Application`) REFERENCES `application` (`PK_Application`) ON DELETE CASCADE ON UPDATE CASCADE;

当此文件输入到 mysql.exe 或表已存在时的 phpMyAdmin 导入函数时,表applicationproduct_x_applicationDROP 语句application成功,但随后的 CREATE TABLE 语句失败,并显示:

ERROR 1215 (HY000): 无法添加外键约束

但是,如果我首先删除具有引用 tableproduct_x_application的外键约束的表,则 CREATE TABLE 语句会成功。product_x_application_ibfk_2application

从那以后,我了解了更多信息。我走到我的生产机器上,它运行带有 MySql 5.5 服务器和 phpMyAdmin 4.4.23 phpMyAdmin 的 Linux,并且只导出了两个有问题的表,并且能够将生成的文件导入我的 MySql 5.6.27 服务器. 这是两个完整的导出文件(仅结构)。首先来自有问题的 5.6.27 服务器:

-- phpMyAdmin SQL Dump
-- version 4.4.15
-- http://www.phpmyadmin.net
--
-- Host: localhost
-- Generation Time: Jan 10, 2016 at 07:01 AM
-- Server version: 5.6.26-log
-- PHP Version: 5.6.12

SET FOREIGN_KEY_CHECKS=0;
SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO";
SET time_zone = "+00:00";


/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8mb4 */;

--
-- Database: `spmorell_sami`
--

-- --------------------------------------------------------

--
-- Table structure for table `application`
--

DROP TABLE IF EXISTS `application`;
CREATE TABLE `application` (
  `PK_Application` int(11) NOT NULL,
  `FK_Parent` int(11) DEFAULT NULL,
  `ApplicationLevel` tinyint(4) NOT NULL,
  `Description` varchar(35) NOT NULL,
  `Sequence` tinyint(4) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

-- --------------------------------------------------------

--
-- Table structure for table `product_x_application`
--

DROP TABLE IF EXISTS `product_x_application`;
CREATE TABLE `product_x_application` (
  `PK_Product_X_Application` int(11) NOT NULL,
  `Product_PKID` varchar(36) NOT NULL,
  `FK_Application` int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

--
-- Indexes for dumped tables
--

--
-- Indexes for table `application`
--
ALTER TABLE `application`
  ADD PRIMARY KEY (`PK_Application`);

--
-- Indexes for table `product_x_application`
--
ALTER TABLE `product_x_application`
  ADD PRIMARY KEY (`PK_Product_X_Application`),
  ADD KEY `Product_PKID` (`Product_PKID`),
  ADD KEY `FK_Application` (`FK_Application`);

--
-- AUTO_INCREMENT for dumped tables
--

--
-- AUTO_INCREMENT for table `application`
--
ALTER TABLE `application`
  MODIFY `PK_Application` int(11) NOT NULL AUTO_INCREMENT;
--
-- AUTO_INCREMENT for table `product_x_application`
--
ALTER TABLE `product_x_application`
  MODIFY `PK_Product_X_Application` int(11) NOT NULL AUTO_INCREMENT;
--
-- Constraints for dumped tables
--

--
-- Constraints for table `product_x_application`
--
ALTER TABLE `product_x_application`
  ADD CONSTRAINT `product_x_application_ibfk_1` FOREIGN KEY (`Product_PKID`) REFERENCES `product` (`Product_PKID`) ON DELETE CASCADE ON UPDATE CASCADE,
  ADD CONSTRAINT `product_x_application_ibfk_2` FOREIGN KEY (`FK_Application`) REFERENCES `application` (`PK_Application`) ON DELETE CASCADE ON UPDATE CASCADE;
SET FOREIGN_KEY_CHECKS=1;

/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;

请注意,表的主键application是在 ALTER TABLE 语句中定义的。这是从 5.5 服务器导出的文件:

-- phpMyAdmin SQL Dump
-- version 3.5.8.2
-- http://www.phpmyadmin.net
--
-- Host: localhost
-- Generation Time: Jan 10, 2016 at 05:09 AM
-- Server version: 5.5.42-37.1-log
-- PHP Version: 5.4.23

SET FOREIGN_KEY_CHECKS=0;
SET SQL_MODE="NO_AUTO_VALUE_ON_ZERO";
SET time_zone = "+00:00";

--
-- Database: `spmorell_sami`
--

-- --------------------------------------------------------

--
-- Table structure for table `application`
--

DROP TABLE IF EXISTS `application`;
CREATE TABLE `application` (
  `PK_Application` int(11) NOT NULL AUTO_INCREMENT,
  `FK_Parent` int(11) DEFAULT NULL,
  `ApplicationLevel` tinyint(4) NOT NULL,
  `Description` varchar(35) NOT NULL,
  `Sequence` tinyint(4) NOT NULL,
  PRIMARY KEY (`PK_Application`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=15 ;

-- --------------------------------------------------------

--
-- Table structure for table `product_x_application`
--

DROP TABLE IF EXISTS `product_x_application`;
CREATE TABLE `product_x_application` (
  `PK_Product_X_Application` int(11) NOT NULL AUTO_INCREMENT,
  `Product_PKID` varchar(36) NOT NULL,
  `FK_Application` int(11) NOT NULL,
  PRIMARY KEY (`PK_Product_X_Application`),
  KEY `Product_PKID` (`Product_PKID`),
  KEY `FK_Application` (`FK_Application`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=1633 ;

--
-- Constraints for dumped tables
--

--
-- Constraints for table `product_x_application`
--
ALTER TABLE `product_x_application`
  ADD CONSTRAINT `product_x_application_ibfk_2` FOREIGN KEY (`FK_Application`) REFERENCES `application` (`PK_Application`) ON DELETE CASCADE ON UPDATE CASCADE,
  ADD CONSTRAINT `product_x_application_ibfk_1` FOREIGN KEY (`Product_PKID`) REFERENCES `product` (`Product_PKID`) ON DELETE CASCADE ON UPDATE CASCADE;
SET FOREIGN_KEY_CHECKS=1;

这里表的主键是在application定义表时立即定义的。我认为问题在于,product_x_application在系统尝试重新创建application表时已经存在的表具有对表的外键约束,当重新创建时,该表在外键上没有所需的索引,因为主密钥尚未定义。

4

2 回答 2

1

外键应引用唯一列(例如,主键)。PK_Application,目前,不是这样的专栏。不过,从它的名字来看,您似乎打算将它作为主键:

ALTER TABLE `application` 
ADD CONSTRAINT `application_pk` PRIMARY KEY (`PK_Application`);
于 2016-01-09T18:52:02.990 回答
0

我还有更多信息。我已经安装了更高版本的 phpMyAdmin (4.5.0.2),但忘记了。为了咯咯笑,我决定用它来做出口。和以前一样,我将 ADD DROP TABLE 指定为选项(自动选中 ADD CREATE TABLE 并且不能取消选中)。但是现在,在 ADD CREATE TABLE 的 IF NOT EXISTS 子选项旁边,它在括号中说:“(效率较低,因为在创建表期间会生成索引)”,这当然正是我需要的(通常我不会认为检查此选项,因为我知道该表此时不可能存在)。输出是:

-- phpMyAdmin SQL Dump
-- version 4.5.0.2
-- http://www.phpmyadmin.net
--
-- Host: localhost
-- Generation Time: Jan 10, 2016 at 07:54 AM
-- Server version: 5.6.26-log
-- PHP Version: 5.6.12

SET FOREIGN_KEY_CHECKS=0;
SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO";
SET time_zone = "+00:00";

--
-- Database: `spmorell_sami`
--

-- --------------------------------------------------------

--
-- Table structure for table `application`
--

DROP TABLE IF EXISTS `application`;
CREATE TABLE IF NOT EXISTS `application` (
  `PK_Application` int(11) NOT NULL AUTO_INCREMENT,
  `FK_Parent` int(11) DEFAULT NULL,
  `ApplicationLevel` tinyint(4) NOT NULL,
  `Description` varchar(35) NOT NULL,
  `Sequence` tinyint(4) NOT NULL,
  PRIMARY KEY (`PK_Application`)
) ENGINE=InnoDB AUTO_INCREMENT=15 DEFAULT CHARSET=latin1;

-- --------------------------------------------------------

--
-- Table structure for table `product_x_application`
--

DROP TABLE IF EXISTS `product_x_application`;
CREATE TABLE IF NOT EXISTS `product_x_application` (
  `PK_Product_X_Application` int(11) NOT NULL AUTO_INCREMENT,
  `Product_PKID` varchar(36) NOT NULL,
  `FK_Application` int(11) NOT NULL,
  PRIMARY KEY (`PK_Product_X_Application`),
  KEY `Product_PKID` (`Product_PKID`),
  KEY `FK_Application` (`FK_Application`)
) ENGINE=InnoDB AUTO_INCREMENT=1633 DEFAULT CHARSET=latin1;

--
-- Constraints for dumped tables
--

--
-- Constraints for table `product_x_application`
--
ALTER TABLE `product_x_application`
  ADD CONSTRAINT `product_x_application_ibfk_1` FOREIGN KEY (`Product_PKID`) REFERENCES `product` (`Product_PKID`) ON DELETE CASCADE ON UPDATE CASCADE,
  ADD CONSTRAINT `product_x_application_ibfk_2` FOREIGN KEY (`FK_Application`) REFERENCES `application` (`PK_Application`) ON DELETE CASCADE ON UPDATE CASCADE;
SET FOREIGN_KEY_CHECKS=1;

所以问题一直是 phpMyadmin 4.4.15 版本而不是 MySql 版本。显然,我一直在定期升级 phpMyAdmin 版本,我可以推断出我从来没有机会使用有问题的(至少对我而言)phpMyAdmin 版本 4.4.15 运行导入。

于 2016-01-10T13:23:59.090 回答