
create table tb1(姓名 varchar(10),课程 varchar(10),分数 int);
insert into tb1 values('张三','语文',74);
insert into tb1 values('张三','数学',83);
insert into tb1 values('张三','物理',93);
insert into tb1 values('李四','语文',74);
insert into tb1 values('李四','数学',84);
insert into tb1 values('李四','物理',94) ;
select * from tb1;
select t.*,100 as "表现" from tb1 t;
select *,(select case when 分数>=85 then "优秀"
else "666" end as "表现") from tb1 ;


