-- 查詢課程編號為“01”的課程比“02”的課程成績高的所有學(xué)生的學(xué)號select s_id, s_score from score where c_id ='01';select s_id, s_score from score where c_id ='02';select a.s_id from(select s_id, s_score from score where c_id ='01') ainnerjoin(select s_id, s_score from score where c_id ='02') b on a.s_id = b.s_id
where a.s_score > b.s_score;
-- 查詢所有學(xué)生的學(xué)號、姓名、選課數(shù)、總成績select student.s_id, s_name,count(c_id),sum(casewhen s_score isnullthen0else s_score end)from studentleftjoin score s on student.s_id = s.s_id
groupby student.s_id, s_name;
查詢沒學(xué)過張三老師課程的學(xué)生的學(xué)號和姓名;
-- 查詢沒學(xué)過張三老師課程的學(xué)生的學(xué)號和姓名;select student.s_id
from studentinnerjoin score s on student.s_id = s.s_idinnerjoin course c on s.c_id = c.c_idinnerjoin teacher t on c.t_id = t.t_id
where t_name ='張三';select s_id, s_name
from student
where s_id notin(select student.s_idfrom studentinnerjoin score s on student.s_id = s.s_idinnerjoin course c on s.c_id = c.c_idinnerjoin teacher t on c.t_id = t.t_idwhere t_name ='張三');