在MySQL5中添加复合外键失败

我试图强制用户的地址信息中的州/省和国家名称来自我列出国家和州/省的一组表格.为了做到这一点,我尝试运行这样的alter table命令……

ALTER TABLE User
    ADD FOREIGN KEY (stateProvince,country)
    REFERENCES `StateProvince`(`name`,`countryName`);

然后我收到这条消息……

Create table ‘realtorprint_dev/#sql-d5c_3d’ with foreign key
constraint failed. There is no index in the referenced table where the
referenced columns appear as the first columns.

有没有人知道如何处理此错误消息？

这是州和国家表的创建……

CREATE TABLE Country (
  name varchar(40) NOT NULL,
  abbreviation varchar(4) NOT NULL,
  PRIMARY KEY  (name)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8;

CREATE TABLE StateProvince (
  countryName varchar(40) NOT NULL,
  name varchar(100) NOT NULL,
  abbreviation varchar(3) NOT NULL,
  PRIMARY KEY  (countryName,name)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

alter table StateProvince
add constraint FK_StateProvince_Country
foreign key (countryName)
references Country (name);

现在对于用户表…

create table realtorprint_dev.user (
  id bigint not null,
  created datetime,
  email varchar(255) not null,
  fax varchar(255),
  mobile varchar(255),
  name varchar(255),
  password varchar(255),
  phone varchar(255),
  title varchar(255),
  tollFree varchar(255),
  updated datetime,
  web varchar(255),
  brokerage_id bigint,
  address varchar(255),
  city varchar(255),
  country varchar(255),
  stateProvince varchar(255),
  type varchar(255),
  zipPostal varchar(255),
  activated bit not null,
  locked bit not null,
  primary key (id),
  foreign key FK285FEB6722226 (brokerage_id) references brokerage(id)
);

解决方法:

There is no index in the referenced table where the referenced columns appear as the first columns.

你需要StateProvince.(name,countryName)的索引,但是你有一个StateProvince的索引.(countryName,name).尝试颠倒索引或FK参考的顺序.

标签：composite-key,mysql,foreign-key-relationship,mysql5
来源： https://codeday.me/bug/20190903/1795968.html