1.准备 create table newtable ( name ), yuwen ), shuxue ) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; , ); , ); , ); , ); , ); 2.实现 select yuwentable.name studentname,yuwentable.yuwen yuwenscore ,cast(yuwentable.rank as SIGNED) yuwenrank,shuxuetable.shuxue sh