我只想将连接字符串中的唯一值放在一起。我的代码目前是:
select rc.Routage
, COUNT(distinct rc.Event)
, STUFF((select ', ' + cast(rcA.Event as varchar)
from Receiving rcA
where rcA.supplier = 'user'
and rcA.DATETIME > '20170322'
and rc.Routage=rcA.Routage
for xml path(''))
, 1, 1, '')
from Receiving rc
where rc.supplier = 'user'
and rc.DATETIME > '20170322'
group by rc.Routage
order by COUNT(distinct rc.Event)desc
这给了我期望的输出,但我想消除 stuff/for xml 路径字段中的重复值。
我尝试了
distinct
的各种组合和 group by
在 stuff/xml 部分,但无法将其正确拼凑在一起。澄清一下,对于
COUNT(distinct rc.Event)
= 2,我想从 stuff 子句中看到 2 个不同的事件。我怎样才能做到这一点?
最佳答案
使用 select distinct
在子查询中:
select rc.Routage,
count(distinct rc.Event),
stuff((select distinct ', ' + cast(rcA.Event as varchar(max))
from Receiving rcA
where rcA.supplier = 'user' and
rcA.DATETIME > '20170322' and
rc.Routage = rcA.Routage
for xml path('')
), 1, 2, '')
from Receiving rc
where rc.supplier = 'user' and rc.DATETIME > '20170322'
group by rc.Routage;
笔记:
varchar()
(或相关类型)没有长度。默认值因上下文而异,您(可能)引入了一个很难找到的错误。 stuff()
删除两个字符,而不是 1,因为您有一个逗号后跟一个空格。 Event
没有 XML 特殊字符。如果这是一个问题,很容易调整。 此外,如果您消除子查询中的重复项,这种类型的查询通常会更快:
select rc.Routage, rc.numEvents,
stuff((select distinct ', ' + cast(rcA.Event as varchar(max))
from Receiving rcA
where rcA.supplier = 'user' and
rcA.DATETIME > '20170322' and
rc.Routage = rcA.Routage
for xml path(''), type
).value('.', 'varchar(max)'
), 1, 2, ''
)
from (select rc.Routage, count(distinct rc.Event) as numEvents
from Receiving rc
where rc.supplier = 'user' and rc.DATETIME > '20170322'
group by rc.Routage
) rc;
关于sql - 使用不同的东西/for xml 路径 ('' ),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/42975074/