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mysql 创建表和外键

mysql> create table country(
   > country_id smallint unsigned not null auto_increment,
   >country varchar(50) not null,
     >last_update timestamp not null default current_timestamp on update current_timestamp,
     >primary key (country_id)
   >)engine=InnoDB default charset = utf8;

 

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mysql> ccreate table city(
  >city_id smallint unsigned not null auto_increment,
  >city varchar(50) not null,
  >country_id smallint unsigned not null,
  >last_update timestamp not null default current_timestamp on update current_timestamp,
  >primary key (city_id),
  >key idx_fk_country_id (country_id),
  >foreign key (country_id) references country (country_id)
  >) ENGINE = InnoDB default charset=utf8;

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mysql 创建表和外键