kwhw.net
当前位置:首页 >> orAClE三表联合查询 >>

orAClE三表联合查询

比如有三张表,student,teacher , project : 第一种方法:select * from student,teacher,project where student.id=teacher.sid and student.id=project.sid; 第二种:select * from student inner join teacher on student.id=teacher.sid i...

select A.姓名,A.性别,D.选课内容 from Aleft join (SELECT B.学号 student, wmsys.wm_concat (C.课程名称) as 选课内容 FROM Bleft join C on B.课程id = C.课程IDGROUP BY B.学号) as D on A.学号 = D.学号

大哥你以B为主表查埃。以A去LEFT JOIN肯定会多的! select b.sheetid,b.productid,c.name,b.number,a.companyid,a.ordertimefrom orderitem b left join order a on b.sheetid = a.sheetid left join product c on b.productid = c.productid

-- User不能用作表名,用tUser作名DROP TABLE tUser;CREATE TABLE tUser ( UserID NUMBER,UserName VARCHAR2(10),UserRole VARCHAR2(10),RealName VARCHAR2(10));INSERT INTO tUser (UserID,UserName,UserRole,RealName) VALUES (1,'wll','职工'...

select A.*,B.*,C.* from TB_EC_ACT_ORD A,TB_EC_ORD_EQPT B,TB_PM_EQPT C where A.SEQ_ID = B.SEQ_ID and B.EQPT_ID=C.EQPT_ID;

学生表student no(学号) name(姓名) 科目表subject kid(学科代号) kname(学科名字) 成绩表mark no(学号) kid(学科代码) mark(成绩) 查询语句: SELECT student.name, subject.kname, mark.mark FROM student, subject, mark WHERE mar...

以oracle使用rownum伪列实现分页为例: 三表连接分页示例代码如下: select * from (select rownum r,k.kch,k.kcm,cj.cj,x.xh,x.xm from KCB k,CJB cj,XSB x where k.kch = cj.kch and cj.xh = x.xh and rownum0 特别注意这样外层查询时由于内层...

第一种方法:select * from student,teacher,project where student.id=teacher.sid and student.id=project.sid; 第二种:select * from student inner join teacher on student.id=teacher.sid inner join project on student.id=project.sid...

使用内链接就可以解决的。可以将你的申请了语句贴出来看看那里有重复数据。 参考sql语句: select a.*,b.*,c.* from goods a inner join smalltype b on a.smalltypeid=b.smalltypeid inner join bigtype c on b.bigtypeid =c.bigtypeid

select a.*,c.f from (select * from a inner join b on a.a = b.a) as a inner join c on a.d = c.d select a.*,c.f from a inner join b on a.a = b.a inner join b.d = b.d 两个都可以,第一个更容易理解 括号里的部分 是查询出 查询表A的数...

网站首页 | 网站地图
All rights reserved Powered by www.kwhw.net
copyright ©right 2010-2021。
内容来自网络,如有侵犯请联系客服。zhit325@qq.com