Sql 当与表联接时,避免每个实例的行重复
嗨,我有3张桌子,我正试图加入他们,以得到一张渴望的桌子。我尝试了group by和temp tables选项以获得所需的表格,但没有任何帮助。我希望避免一个表中的值的每个实例与另一个表中的值重复 表1客户表:Sql 当与表联接时,避免每个实例的行重复,sql,sql-server-2008,tsql,Sql,Sql Server 2008,Tsql,嗨,我有3张桌子,我正试图加入他们,以得到一张渴望的桌子。我尝试了group by和temp tables选项以获得所需的表格,但没有任何帮助。我希望避免一个表中的值的每个实例与另一个表中的值重复 表1客户表: CstId CstDetails CstType ---------- --------------- ------------ 1 address 1 1 2 addres
CstId CstDetails CstType
---------- --------------- ------------
1 address 1 1
2 address 2 1
3 address 3 1
4 address 4 2
5 address 5 2
表2客户关系:
CstId CstGroupId
---------- ----------------
1 4 (this is same as CustomerId)
2 5 (this is same as CustomerId)
3 4 (this is same as CustomerId)
表3客户注意事项:
CstId NotesId NoteTxt
----------- --------- ---------
1 1 note11
1 2 note12
1 3 note13
3 1 note31
4 1 note41
4 2 note42
4 3 note43
4 4 note44
4 5 note45
现在我希望结果的格式如下
Table result:
(NoteId) (Notetxt) (NoteId) (Notetxt)
CstId CstDetails CstGroupId CstNoteId CstNote CstGroupNoteId CstGroupNote
1 address1 4 1 note11 1 note41
1 address1 4 2 note12 2 note42
1 address1 4 3 note13 3 note43
1 address1 4 null null 4 note44
1 address1 4 null null 5 note45
但是我让CstGroupNote对所有CstNote进行重复,这是我试图避免的
有什么方法可以达到这个效果吗
下面是我使用的代码:
select c.cstid, c.cstdetails, cn.cstnotesid, cn.cstnotetxt
insert into temp1
from customer c
left outer join customernotes cn
on c.cstid = cn.cstid
where c.customertypeid = 1
select cr.cstid, cr.cstgroupid, cn.cstgroupnoteid, cn.cstnotetxt
insert into temp2
from customerrelationship cr
left outer join customernotes cn
on cr.cstgroupid = cn.customerid
select t1.cstid, t1.cstdetails, t1.cstnotesid, t1.cstnotetxt, t2.cstgroupnoteid, t2.cstnotetext
from temp1 t1
left outer join t2
on t1.cstid = t2.cstid
尝试:
使用派生表和外部联接
这里的诀窍是
和cn.cstnotesid=cG.cstnotesid
将这两个链接到一行
select c.cstid, c.cstdetails, cn.cstnotesid, cn.cstnotetxt
,cG.CstGroupId, cG.cstnotesid, cG.cstnotetxt
from customer c
join customernotes cn
on cn.cstid = c.cstid
outer join (select c.cstid, c.CstGroupId, cn.cstnotesid, cn.cstnotetxt
from customer c
join customernotes cn
on cn.cstid = c.CstGroupId) as cG
on c.cstid = cG.cstid
and cn.cstnotesid = cG.cstnotesid
order by c.cstid, cn.cstnotesid, cG.cstnotesid
到目前为止,您的查询是什么?我已经创建了两个临时表,一个用于获取customernotes,另一个用于获取groupnotes,然后使用基于CustomerID的左外部联接联接联接两个临时表。下面是我使用的代码:选择c.cstid、c.cstdetails、cn.cstnotesid,cn.cstnotetxt从客户c插入temp1左侧外部连接客户备注cn在c.cstid=cn.cstid上其中c.customertypeid=1选择cr.cstid,cr.cstgroupid,cn.cstgroupnoteid,cn.cstnotetxt从客户关系cr左侧外部连接客户备注cn在cr.cstgroupid=cn.customerid选择t1.cstid,t1.cstdetails,t1.cstnotesid、t1.cstnotetxt、t2.cstgroupnoteid、t2.cstnotetext来自t1.cstid=t2.cstid上的temp1 t1左外部联接t2您作为示例提供的表缺少列!在查询示例中,它们有更多的列。我们需要它们的数据,以便将其与您提供的所需表相匹配CstNoteId是noteid的别名,cstnotetxt是notetxt的别名cstgroupnoteid和CstGroupNoteTXT的情况相同谢谢,但您的解决方案只有在notesid匹配时才起作用,而在我的情况下,它并非始终为真。感谢您的解决方案,它真的帮助了我。@user2091818:很高兴我能帮上忙。
select c.cstid, c.cstdetails, cn.cstnotesid, cn.cstnotetxt
,cG.CstGroupId, cG.cstnotesid, cG.cstnotetxt
from customer c
join customernotes cn
on cn.cstid = c.cstid
outer join (select c.cstid, c.CstGroupId, cn.cstnotesid, cn.cstnotetxt
from customer c
join customernotes cn
on cn.cstid = c.CstGroupId) as cG
on c.cstid = cG.cstid
and cn.cstnotesid = cG.cstnotesid
order by c.cstid, cn.cstnotesid, cG.cstnotesid