主要目的是想将bd_psnbasdoc,bd_psndoc,hi_psndoc_deptchg这三张表的部分数据抽取出来形成展现在一块,但是我写了一段出来,同一个人的信息出现了很多重复的记录,求帮助!select bd_psnbasdoc.pk_psnbasdoc,bd_psnbasdoc.psnname,bd_psnbasdoc.pk_corp,hi_psndoc_deptchg.pk_postdoc,
hi_psndoc_deptchg.pk_jobserial,hi_psndoc_deptchg.pk_psncl,hi_psndoc_deptchg.pk_dutyrank,bd_psndoc.groupdef1,
bd_psndoc.groupdef6,bd_psndoc.groupdef3,bd_psnbasdoc.employform,bd_psndoc.groupdef2,bd_psndoc.groupdef4,
bd_psndoc.poststat,bd_psnbasdoc.penelauth,hi_psndoc_deptchg.begindate,bd_psndoc.insource
from bd_psndoc inner join hi_psndoc_deptchg on bd_psndoc.pk_psncl=hi_psndoc_deptchg.pk_psncl
inner join bd_psnbasdoc on bd_psnbasdoc.psnname=bd_psndoc.psnname
hi_psndoc_deptchg.pk_jobserial,hi_psndoc_deptchg.pk_psncl,hi_psndoc_deptchg.pk_dutyrank,bd_psndoc.groupdef1,
bd_psndoc.groupdef6,bd_psndoc.groupdef3,bd_psnbasdoc.employform,bd_psndoc.groupdef2,bd_psndoc.groupdef4,
bd_psndoc.poststat,bd_psnbasdoc.penelauth,hi_psndoc_deptchg.begindate,bd_psndoc.insource
from bd_psndoc inner join hi_psndoc_deptchg on bd_psndoc.pk_psncl=hi_psndoc_deptchg.pk_psncl
inner join bd_psnbasdoc on bd_psnbasdoc.psnname=bd_psndoc.psnname
select a.pk_psnbasdoc,a.psnname,a.pk_corp,b.pk_postdoc,
b.pk_jobserial,b.pk_psncl,b.pk_dutyrank,c.groupdef1,
c.groupdef6,c.groupdef3,c.groupdef2,c.groupdef4,
bd_psnbasdoc.employform, --bd_psnbasdoc未访问的表
c.poststat,a.penelauth,b.begindate,c.insource
from bd_psndoc c inner join hi_psndoc_deptchg b on c.pk_psncl=b.pk_psncl
inner join bd_psnbasdoc a on a.psnname=c.psnname
LZ有发现 还一个表(bd_psnbasdoc)没确定关系么? 如何来连接这个表 确定应该就没重复了吧?
b.pk_jobserial,b.pk_psncl,b.pk_dutyrank,c.groupdef1,
c.groupdef6,c.groupdef3,c.groupdef2,c.groupdef4,
a.employform,c.poststat,a.penelauth,b.begindate,c.insource
from bd_psndoc c inner join hi_psndoc_deptchg b on c.pk_psncl=b.pk_psncl
inner join bd_psnbasdoc a on a.psnname=c.psnname
先发下表的关系吧
select distinct a.pk_psnbasdoc,a.psnname,a.pk_corp,b.pk_postdoc,
b.pk_jobserial,b.pk_psncl,b.pk_dutyrank,c.groupdef1,
c.groupdef6,c.groupdef3,c.groupdef2,c.groupdef4,
a.employform,c.poststat,a.penelauth,b.begindate,c.insource
from bd_psndoc c,bd_psnbasdoc a,hi_psndoc_deptchg b
where c.pk_psncl=b.pk_psncl and a.psnname=c.psnname
重复字段是哪些 关系是不是唯一?