不小心到DB2版找到的这道题:阿里baba的面试题有三个表
学生表 S
SID SNAME
教师课表 T
TID TNAME TCL
成绩表 SC
SID TCL SCR
各字段的含义不用我标明了吧,大侠哥哥么!呵呵现在要求写SQL查询
1、选修了A、B课程,并且A课程的成绩大于B成绩的学生姓名?
学生表 S
SID SNAME
教师课表 T
TID TNAME TCL
成绩表 SC
SID TCL SCR
各字段的含义不用我标明了吧,大侠哥哥么!呵呵现在要求写SQL查询
1、选修了A、B课程,并且A课程的成绩大于B成绩的学生姓名?
FROM S, SC T1, SC T2
WHERE S.SID = T1.SID
AND S.SID = T2.SID
AND T1.TCL = 'A'
AND T2.TCL = 'B'
AND T1.SCR > T2.SCR
FROM s
WHERE EXISTS (SELECT sc1.sid, sc2.sid
FROM sc sc1 INNSER JOIN sc sc2 ON sc1.sid=sc2.sid AND sc1.tcl='A' AND sc2.tcl='B' AND sc1.scr>sc2.scr
WHERE sc1.sid=s.sid );
SELECT s.sname
FROM s
WHERE EXISTS (SELECT sc1.sid, sc2.sid
FROM sc sc1 INNER JOIN sc sc2 ON sc1.sid=sc2.sid AND sc1.tcl='A' AND sc2.tcl='B' AND sc1.scr>sc2.scr
WHERE sc1.sid=s.sid );
with s as(
select '001' sid,'张三' sname from dual union all
select '002' sid,'李四' sname from dual union all
select '003' sid,'王五' sname from dual), sc as (
select '001' sid,'A' tcl, 80 scr from dual union all
select '001' sid,'B' tcl, 70 scr from dual union all
select '002' sid,'A' tcl, 60 scr from dual union all
select '002' sid,'B' tcl, 80 scr from dual union all
select '003' sid,'A' tcl, 80 scr from dual union all
select '003' sid,'C' tcl, 80 scr from dual)
SELECT s.*
FROM s,
(SELECT a.sid
FROM (SELECT * FROM sc WHERE tcl = 'A') a, (SELECT * FROM sc WHERE tcl = 'B') b
WHERE a.sid = b.sid AND
a.scr > b.scr) t
WHERE s.sid = t.sid--2
with s as(
select '001' sid,'张三' sname from dual union all
select '002' sid,'李四' sname from dual union all
select '003' sid,'王五' sname from dual), sc as (
select '001' sid,'A' tcl, 80 scr from dual union all
select '001' sid,'B' tcl, 70 scr from dual union all
select '002' sid,'A' tcl, 60 scr from dual union all
select '002' sid,'B' tcl, 80 scr from dual union all
select '003' sid,'A' tcl, 80 scr from dual union all
select '003' sid,'C' tcl, 80 scr from dual)
SELECT *
FROM s
WHERE sid IN (SELECT sid
FROM sc a
WHERE EXISTS (SELECT 1
FROM sc b
WHERE b.sid = a.sid AND
a.tcl = 'A' AND
b.tcl = 'B' AND
a.scr > b.scr))
With
s As
(select '1' sid, 'A' sname From dual
Union All select '2' sid, 'B' sname From dual
Union All select '3', 'C' From dual
Union All select '4', 'D' From dual
),sc As
(Select '1' sid, 'A' tcl, 90 scr From dual
Union All Select '1', 'B', 91 From dual
Union All Select '2', 'B', 91 From dual
Union All Select '2', 'A', 90 From dual
Union All Select '3', 'A', 91 From dual
Union All Select '3', 'B', 51 From dual
Union All Select '4', 'A', 61 From dual
)
select t1.sid,s.sname From (
Select sid,scr, sign(scr - nvl(lead(scr)over(Partition By sid Order By tcl),scr)) si From sc
) t1, s
Where t1.si = 1
And t1.sid = s.sid
select sname from s where sid in(select a.sid
from sc a,sc b
where a.sid=b.sid and a.tcl='A' and b.tcl='B' and a.scr>b.scr)
With
s As
(select '1' sid, 'A' sname From dual
Union All select '2' sid, 'B' sname From dual
Union All select '3', 'C' From dual
Union All select '4', 'D' From dual
),sc As
(Select '1' sid, 'A' tcl, 90 scr From dual
Union All Select '1', 'B', 91 From dual
Union All Select '2', 'B', 91 From dual
Union All Select '2', 'A', 90 From dual
Union All Select '3', 'A', 91 From dual
Union All Select '3', 'B', 51 From dual
Union All Select '4', 'A', 61 From dual
)
select t1.sid,s.sname From (
Select sid,scr, sign(scr - nvl(lead(scr)over(Partition By sid Order By tcl),scr)) si From sc
Where tcl = 'A' Or tcl = 'B') t1, s
Where t1.si = 1
And t1.sid = s.sid哦,应该加上一个条件,