简单查询

where grade<60; (5)select ssex,sage,sdept from student

where sdept not in('cs','is'); (6)select sno,grade from sc

where cno='004' order by grade desc

(7)select distinct cno,count(*) from sc group by cno;

(8)select sname,sdept,sage from student where sdept='cs'

(9)select sname,sno,sdept,sage from student

where sage in ('18','19','20'); (10)select * from student

where sname like '刘*' (11)select sno from sc

where cno='001'and sno in (select sno from student where cno='002');

(12)select sname, 2003-sage from student; (13)select sno,cno from sc

where grade is null; (14)select sno from sc group by sno

having count(grade)>200; (15)select count(cno) from sc

where grade<60 group by cno; (16)select sno from sc

where grade<60 group by sno having count(*)>3; (17)select * from student

where sage between 10 and 19; (18)select * from student

order by sdept ,sage desc; (19)select avg(grade) from sc

where cno='001'; (20)select max(grade) from sc

where cno='003'; (21)select sno sum(grade) from sc group by cno;