表简单结构
CREATE TABLE IF NOT EXISTS table_school(
school_id smallint unsigned NOT NULL AUTO_INCREMENT COMMENT '校区id',
city_pid smallint unsigned NOT NULL COMMENT '父级校区所在市id',
school_name varchar(32) NOT NULL DEFAULT '' COMMENT '名称',
school_intro varchar(255) NOT NULL DEFAULT '' COMMENT '简介',
KEY(city_pid),
PRIMARY KEY(school_id)
) ENGINE=innoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 COMMENT '校区表';
SQL
select a.*, (select school_name from table_school where a.city_pid=school_id) as city_name from table_school as a
where a.school_id = :school_id;