您所在位置：主题：请教关于MYSQL的外键约束
jxlanxin
[专家分：100] 发布于 2006-05-31 17:57:00
大家好，本人使用MYSQL建了两张表:country、city，如下：
create table country
(countryId int auto_increment primary key,
countryName varchar(20) not null)type=innoDB;
create table city
(cityId int auto_increment primary key,
cityName varchar(20) not null,
countryName varchar(20) not null references country(countryName) RESTRICT)type=innoDB;
insert into country (countryName) values ('China');
insert into country (countryName) values ('USA');
insert into country (countryName) values ('England');
insert into city (cityName,countryName) values ('NanChang','ABCD');
请问为什么没能阻止最后一行代码的执行？
官方网站[color=008080]http://dev.mysql.com/doc/refman/5.0/en/innodb-foreign-key-constraints.html[/color]看完也没有相关解释，挺郁闷，求教，谢谢！
create table country
(countryId int auto_increment primary key,
countryName varchar(20) not null)type=innoDB;
create table city
(cityId int auto_increment primary key,
cityName varchar(20) not null,
countryName varchar(20) not null references country(countryName) RESTRICT)type=innoDB;
insert into country (countryName) values ('China');
insert into country (countryName) values ('USA');
insert into country (countryName) values ('England');
insert into city (cityName,countryName) values ('NanChang','ABCD');
请问为什么没能阻止最后一行代码的执行？
官方网站[color=008080]http://dev.mysql.com/doc/refman/5.0/en/innodb-foreign-key-constraints.html[/color]看完也没有相关解释，挺郁闷，求教，谢谢！