oracle三张表的连接查询
@边绍6600：关于oracle多表联合查询的语句如何写? -
鬱佩18155665720…… 我给你写一个,保证能用,验证能用的话请采纳!!!select all_.bh,all_.name,a.sl,b.sl1,c.sl2,c.sl3 from( select bh,name from a union select bh,name from b union select bh,name from c) all_ left outer join a on all_.bh = a.bh and all_.name = a.name...
@边绍6600：oracle中如何将多个查询结果在一张表中显示 -
鬱佩18155665720…… 可以将你的三个表的查询结果使用union all联合起来,然后使用Oracle的decode函数来查询 select 姓名,sum(decode(tbname,'表1',人数,null)) 表1人数,sum(decode(tbname,'表2',人数,null)) 表2人数,sum(decode(tbname,'表3',人数,...
@边绍6600：求三表联合查询的SQL查询语句 -
鬱佩18155665720…… 车讯语句:select username,psw from (a1 left join a2 on a1.a1_id=a2.a1_id) left join a3 on a1.a1_id=a3.a1_id 这样写: SELECT S.SName AS 姓名, CS.CourseName AS 课程, C.Score AS 成绩 FROM Students AS S INNER JOIN Score AS C ...
@边绍6600：oracle怎么实现多表 连接查询 并分页... -
鬱佩18155665720…… 多表连接最好一次从数据库中取出,在前台分页,否则每次做连接很耗费资源的.从技术上你的写法也是对的:select * from (select rownum as r,u.userid,u.userid,u.loginName,t.content from userinfo u,twitter t where u.userid=t.userid and loginname like '%java%')t where rownum<= currentPage*pageSize and rownum<= (currentPage+1)*pageSize 你试下.
@边绍6600：oracle关联三张表查询太慢 -
鬱佩18155665720…… select a.id,a.name,max(b.num) from a,b where a.id = b.id and exists( select 1 from c where b.nid = c.nid) group by a.id,a.name,b.num 使用exists可以减少很多次数据关联的次数,试试看,如果满意请加分,谢谢!
@边绍6600：oracle 中多表连接如何用 -
鬱佩18155665720…… 以两表为例: 有以下两张表:现在要通过deptno字段,在查询中显示emp表中全部内容和dept表中的dname字段. 可用如下语句: select a.*,b.dname from emp a,dept b where a.deptno=b.deptno; 查询结果:
@边绍6600：用oracle存储过程将三张表的数据查出插入另三张表 -
鬱佩18155665720…… PROCEDURE P1 IS BEGIN DELETE FROM A1; DELETE FROM B1; DELETE FROM C1; INSERT INTO A1 SELECT * FROM A; INSERT INTO B1 SELECT * FROM B; INSERT INTO C1 SELECT * FROM C; INSERT INTO A2 SELECT * FROM A;...
@边绍6600：oracle 想把三张表关联起来,怎么关联? -
鬱佩18155665720…… WHERE条件里写 sysuser.yhdh=usermenu.yhdh and usermenu.cxdh=program.cxdh 例如:select * from sysuser,usermenu,program where sysuser.yhdh=usermenu.yhdh and usermenu.cxdh=program.cxdh 这样三张表就关联了.
@边绍6600：oracle数据库多表连接查询 -
鬱佩18155665720…… 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查询的字段有重复列名,所以内层查询最后不要用*.取完每一个表字段,这样很容易报错(“无效字段”)
@边绍6600：oracle 3表联合查询问题 -
鬱佩18155665720…… select s.s#,s.sn from s,c,sc where s.s#=sc.s# and c.c#=sc.c# and c.cn='数学'
鬱佩18155665720…… 我给你写一个,保证能用,验证能用的话请采纳!!!select all_.bh,all_.name,a.sl,b.sl1,c.sl2,c.sl3 from( select bh,name from a union select bh,name from b union select bh,name from c) all_ left outer join a on all_.bh = a.bh and all_.name = a.name...
@边绍6600：oracle中如何将多个查询结果在一张表中显示 -
鬱佩18155665720…… 可以将你的三个表的查询结果使用union all联合起来,然后使用Oracle的decode函数来查询 select 姓名,sum(decode(tbname,'表1',人数,null)) 表1人数,sum(decode(tbname,'表2',人数,null)) 表2人数,sum(decode(tbname,'表3',人数,...
@边绍6600：求三表联合查询的SQL查询语句 -
鬱佩18155665720…… 车讯语句:select username,psw from (a1 left join a2 on a1.a1_id=a2.a1_id) left join a3 on a1.a1_id=a3.a1_id 这样写: SELECT S.SName AS 姓名, CS.CourseName AS 课程, C.Score AS 成绩 FROM Students AS S INNER JOIN Score AS C ...
@边绍6600：oracle怎么实现多表 连接查询 并分页... -
鬱佩18155665720…… 多表连接最好一次从数据库中取出,在前台分页,否则每次做连接很耗费资源的.从技术上你的写法也是对的:select * from (select rownum as r,u.userid,u.userid,u.loginName,t.content from userinfo u,twitter t where u.userid=t.userid and loginname like '%java%')t where rownum<= currentPage*pageSize and rownum<= (currentPage+1)*pageSize 你试下.
@边绍6600：oracle关联三张表查询太慢 -
鬱佩18155665720…… select a.id,a.name,max(b.num) from a,b where a.id = b.id and exists( select 1 from c where b.nid = c.nid) group by a.id,a.name,b.num 使用exists可以减少很多次数据关联的次数,试试看,如果满意请加分,谢谢!
@边绍6600：oracle 中多表连接如何用 -
鬱佩18155665720…… 以两表为例: 有以下两张表:现在要通过deptno字段,在查询中显示emp表中全部内容和dept表中的dname字段. 可用如下语句: select a.*,b.dname from emp a,dept b where a.deptno=b.deptno; 查询结果:
@边绍6600：用oracle存储过程将三张表的数据查出插入另三张表 -
鬱佩18155665720…… PROCEDURE P1 IS BEGIN DELETE FROM A1; DELETE FROM B1; DELETE FROM C1; INSERT INTO A1 SELECT * FROM A; INSERT INTO B1 SELECT * FROM B; INSERT INTO C1 SELECT * FROM C; INSERT INTO A2 SELECT * FROM A;...
@边绍6600：oracle 想把三张表关联起来,怎么关联? -
鬱佩18155665720…… WHERE条件里写 sysuser.yhdh=usermenu.yhdh and usermenu.cxdh=program.cxdh 例如:select * from sysuser,usermenu,program where sysuser.yhdh=usermenu.yhdh and usermenu.cxdh=program.cxdh 这样三张表就关联了.
@边绍6600：oracle数据库多表连接查询 -
鬱佩18155665720…… 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查询的字段有重复列名,所以内层查询最后不要用*.取完每一个表字段,这样很容易报错(“无效字段”)
@边绍6600：oracle 3表联合查询问题 -
鬱佩18155665720…… select s.s#,s.sn from s,c,sc where s.s#=sc.s# and c.c#=sc.c# and c.cn='数学'
