SQL語句性能比較

create table sc
(
name char(10),
 kc char(10),
 score decimal(5,2)
 )

 insert into sc
values
      ('張三','國語',80),
      ('張三','數學',81),
      ('張三','英語',100),
      ('李四','國語',90),
      ('李四','數學',80),
      ('李四','英語',70),
      ('王五','國語',100),
      ('王五','數學',100),
      ('王五','英語',79)


--查詢groupby
select name from sc group by name having min(score)>=80
--查詢except
select name from sc except (select name from sc where score<80)