用于创建表的MySQL Errno 150（不正确的外键）

Question

我承认在这里已经被问过几次了，并且已经浏览了很多答案。

我知道errno150引用的表具有错误的外键，并且我在这里看到了先前的答案。 我检查了那里的每一种情况，无法解决。 不知道我是否缺少明显的东西。

这是使用MySQL的Java实现，我有一个switch语句，它创建了两个表（目前），如下所示：

//Creates the table with the name given to the function and adds all fields & keys
            switch(tableName){
            case "Address":
                stmt.executeUpdate("CREATE TABLE Address(houseNo INT(4) NOT NULL, "
                        + "firstLine VARCHAR(30) NOT NULL, "
                        + "secondLine VARCHAR(30), "
                        + "city VARCHAR(25) NOT NULL, "
                        + "county VARCHAR(25) NOT NULL, "
                        + "postCode VARCHAR(7) NOT NULL, "
                        + "PRIMARY KEY (houseNo, postCode))");
                break;
            case "Patient":
                stmt.executeUpdate("CREATE TABLE Patient(patientID INT(8) NOT NULL PRIMARY KEY AUTO_INCREMENT, "
                        + "title VARCHAR (10) NOT NULL, "
                        + "forename VARCHAR(15) NOT NULL, "
                        + "surname VARCHAR(25) NOT NULL, "
                        + "dob DATE NOT NULL, "
                        + "phoneNo CHAR(11) NOT NULL, "
                        + "houseNo INT(4) NOT NULL, "
                        + "postCode VARCHAR(7) NOT NULL, "
                        + "amountOwed DECIMAL(5,2) NOT NULL, "
                        + "FOREIGN KEY (houseNo) REFERENCES Address (houseNo), "
                        + "FOREIGN KEY (postCode) REFERENCES Address (postCode))");
                break;
            }

地址创建正确（无外键），患者给出errno150。 相同的引擎，相同的字符集，相同的数据类型（甚至复制粘贴以确保100％的可靠性），新创建的（空）表，它们都是非临时的。

谢谢。

PS我无法使用SHOW ENGINE INNODB STATUS因为我的权限级别不够高。

完整的错误消息：

java.sql.SQLException: Can't create table 'team.Patient' (errno: 150)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:964)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3970)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3906)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2524)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2677)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2545)
    at com.mysql.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1540)
    at com.mysql.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2595)
    at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1468)
    at uk.team.App.makeTable(App.java:146)
    at uk.team.App.setupEnviro(App.java:80)
    at uk.team.App.access$1(App.java:45)
    at uk.team.App$1.run(App.java:33)
    at java.awt.event.InvocationEvent.dispatch(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$500(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)

Answer 1

如果要创建与父表的同一行中的两列都匹配的外键约束，则需要为两列指定单个FOREIGN KEY（而不是为每列指定两个单独的FK约束）。

这对我适用于MySQL 5.6.13：

stmt.executeUpdate("CREATE TABLE Address(houseNo INT(4) NOT NULL, "
        + "firstLine VARCHAR(30) NOT NULL, "
        + "secondLine VARCHAR(30), "
        + "city VARCHAR(25) NOT NULL, "
        + "county VARCHAR(25) NOT NULL, "
        + "postCode VARCHAR(7) NOT NULL, "
        + "PRIMARY KEY (houseNo, postCode))");
stmt.executeUpdate("CREATE TABLE Patient(patientID INT(8) NOT NULL PRIMARY KEY AUTO_INCREMENT, "
        + "title VARCHAR (10) NOT NULL, "
        + "forename VARCHAR(15) NOT NULL, "
        + "surname VARCHAR(25) NOT NULL, "
        + "dob DATE NOT NULL, "
        + "phoneNo CHAR(11) NOT NULL, "
        + "houseNo INT(4) NOT NULL, "
        + "postCode VARCHAR(7) NOT NULL, "
        + "amountOwed DECIMAL(5,2) NOT NULL, "
        + "FOREIGN KEY (houseNo, postCode) REFERENCES Address (houseNo, postCode))");

Answer 2

由于“地址”表没有问题，因此这与“患者”表的引用更相关，并且我假设“团队”是数据库名称：

1. 根据我在这里看到的内容，应该对引用的列进行索引。 您已经创建了两个索引（ houseNo ， postCode ）在一起，为什么不尝试分别为它们创建索引，看看是否对您postCode ？

2. 尽管您提到使用的是相同的引擎，字符集等，但为什么不在上述查询中明确提及它们并运行它们。 您可以在查询中添加ENGINE = InnoDB吗？

如果不适合您，请告诉我。

无法创建表（errno：150）InnoDB添加外键约束

Answer 3

所以答案（更多的妥协）我来到：

switch(tableName){
            case "Address":
                stmt.executeUpdate("CREATE TABLE Address(houseID INT(8) NOT NULL PRIMARY KEY AUTO_INCREMENT, "
                        + "houseNo INT(4) NOT NULL, "
                        + "firstLine VARCHAR(30) NOT NULL, "
                        + "secondLine VARCHAR(30), "
                        + "city VARCHAR(25) NOT NULL, "
                        + "county VARCHAR(25) NOT NULL, "
                        + "postCode VARCHAR(7) NOT NULL)");
                break;
            case "Patient":
                stmt.executeUpdate("CREATE TABLE Patient(patientID INT(8) NOT NULL PRIMARY KEY AUTO_INCREMENT, "
                        + "title VARCHAR (10) NOT NULL, "
                        + "forename VARCHAR(15) NOT NULL, "
                        + "surname VARCHAR(25) NOT NULL, "
                        + "dob DATE NOT NULL, "
                        + "phoneNo CHAR(11) NOT NULL, "
                        + "houseID INT(8) NOT NULL, "
                        + "amountOwed DECIMAL(5,2) NOT NULL, "
                        + "FOREIGN KEY (houseID) REFERENCES Address (houseID))");
                break;
}

在“地址”中创建一个附加字段，其ID是“患者”中的主键和唯一引用的外键。 它不是理想的，但是可以起作用。