Fragen zur Datenbankabfrage, die häufig in Java-Interviews auftauchen

select a.sno from(select sno,score from sc where cno=1) a,(select sno,score from sc where cno=2) bwhere a.score>b.score and a.sno=b.sno

select a.sno as "学号", avg(a.score) as "平均成绩" from(select sno,score from sc) a group by sno having avg(a.score)>60

select a.sno as 学号, b.sname as 姓名,count(a.cno) as 选课数, sum(a.score) as 总成绩from sc a, student bwhere a.sno = b.snogroup by a.sno, b.sname

selectstudent.sno as 学号, student.sname as 姓名, count(sc.cno) as 选课数, sum(score) as 总成绩from student left Outer join sc on student.sno = sc.snogroup by student.sno, sname

selectcount(distinct(tname)) from teacher where tname like '张%‘

select tname as "姓名", count(distinct(tname)) as "人数" from teacher where tname like'张%'group by tname

select student.sno,student.sname from student
where sno not in (select distinct(sc.sno) from sc,course,teacher
where sc.cno=course.cno and teacher.tno=course.tno and teacher.tname='张三')

select sno, sname from studentwhere sno in (select sno from sc where sc.cno = 1)and sno in (select sno from sc where sc.cno = 2)

selectc.sno, c.sname from(select sno from sc where sc.cno = 1) a,(select sno from sc where sc.cno = 2) b,student cwhere a.sno = b.sno and a.sno = c.sno

select student.sno,student.sname from student,sc where student.sno=sc.sno and sc.cno=1and exists( select * from sc as sc_2 where sc_2.sno=sc.sno and sc_2.cno=2)

select a.sno, a.sname from student a, sc bwhere a.sno = b.sno and b.cno in(select c.cno from course c, teacher d where c.tno = d.tno and d.tname = '李四')

select a.sno, a.sname from student a, sc b,(select c.cno from course c, teacher d where c.tno = d.tno and d.tname = '李四') ewhere a.sno = b.sno and b.cno = e.cno

<p style="font-family: "Microsoft Yahei", "Hiragino Sans GB", Helvetica, "Helvetica Neue", 微软雅黑, Tahoma, Arial, sans-serif; white-space: normal;">select a.sno, a.sname from student a,</p><p style="font-family: "Microsoft Yahei", "Hiragino Sans GB", Helvetica, "Helvetica Neue", 微软雅黑, Tahoma, Arial, sans-serif; white-space: normal;">(select sno, score from sc where cno = 1) b,</p><p style="font-family: "Microsoft Yahei", "Hiragino Sans GB", Helvetica, "Helvetica Neue", 微软雅黑, Tahoma, Arial, sans-serif; white-space: normal;">(select sno, score from sc where cno = 2) c</p><p style="font-family: "Microsoft Yahei", "Hiragino Sans GB", Helvetica, "Helvetica Neue", 微软雅黑, Tahoma, Arial, sans-serif; white-space: normal;">where b.score > c.score and b.sno = c.sno and a.sno = b.sno<br/></p>

select sno,sname from studentwhere sno not in (select distinct sno from sc where score > 60)

select distinct a.sno, a.snamefrom student a, sc bwhere a.sno <> 1 and a.sno=b.sno andb.cno in (select cno from sc where sno = 1)

select s.sno,s.sname from student s,(select sc.sno from scwhere sc.cno in (select sc1.cno from sc sc1 where sc1.sno=1)and sc.sno<>1group by sc.sno)r1where r1.sno=s.sno