varchar数据类型返回null的SQL PIVOT

我正在尝试透视sql表中的数据，以便每个记录id只获得一行。但是，我运行的代码始终返回空值作为最终结果

我的表格如下所示：

"Sequence"  "University Issuing Body"**    
"1" "College1"    
"1" "College2"
"2" "College1"    
"2" "College1"    
"2" "College2"

我需要的表格如下所示：

"Sequence"  "University Issuing Body1"  "University Issuing Body2"  "University Issuing Body3"    
"1" "College1"  "College2"  "NULL"
"2" "College1"  "College1"  "College2"

select
     Sequence]
    ,[University Issuing Body_1]
    ,[University Issuing Body_2]
    ,[University Issuing Body_3]

from (
    select
         [Sequence]
        ,[University Issuing Body]
        ,'University Issuing Body' + cast(row_number() over(partition by [Sequence] order by [University Issuing Body]) as varchar(12)) as hdg
    from [AB_DCU_IP_2018].[dbo].[PR_Q_Joined]
    ) d
    pivot(
        max([University Issuing Body])
        for hdg in ([University Issuing Body_1], [University Issuing Body_2], [University Issuing Body_3])
        )pvt

我正在运行的代码如下所示：

"Sequence"  "University Issuing Body1"  "University Issuing Body2"  "University Issuing Body3"    
"1" "College1"  "College2"  "NULL"
"2" "College1"  "College1"  "College2"

select
     Sequence]
    ,[University Issuing Body_1]
    ,[University Issuing Body_2]
    ,[University Issuing Body_3]

from (
    select
         [Sequence]
        ,[University Issuing Body]
        ,'University Issuing Body' + cast(row_number() over(partition by [Sequence] order by [University Issuing Body]) as varchar(12)) as hdg
    from [AB_DCU_IP_2018].[dbo].[PR_Q_Joined]
    ) d
    pivot(
        max([University Issuing Body])
        for hdg in ([University Issuing Body_1], [University Issuing Body_2], [University Issuing Body_3])
        )pvt

但是，当我运行上述代码时，我的所有值都显示为null，并得到以下结果：

"Sequence"  "University Issuing Body_1" "University Issuing Body_2" "University Issuing Body_3"

"1" "NULL"  "NULL"  "NULL"

"2" "NULL"  "NULL"  "NULL"

任何帮助都将非常感谢，因为我一直在网上寻找解决方案，但似乎找不到哪里出了问题

---

提前感谢。

只需使用条件聚合：

select Sequence,
       max(case when seqnum = 1 then [University Issuing Body] end) as University_Issuing_Body_1,
       max(case when seqnum = 2 then [University Issuing Body] end) as University_Issuing_Body_2,
       max(case when seqnum = 3 then [University Issuing Body] end) as University_Issuing_Body_3
from (select pqj.*
             row_number() over (partition by [Sequence] order by [University Issuing Body]) as seqnum
      from [AB_DCU_IP_2018].[dbo].[PR_Q_Joined] pqj
     ) d
group by [University Issuing Body];

如果您确实想使用

pivot

，则没有理由定义

hdg

：

select [Sequence],
       [1] as [University Issuing Body_1], 
       [2] as [University Issuing Body_2], 
       [3] as [University Issuing Body_3]
from (select [Sequence], [University Issuing ,Body]
             row_number() over (partition by [Sequence] order by [University Issuing Body]) as seqnum
      from [AB_DCU_IP_2018].[dbo].[PR_Q_Joined]
     ) d
pivot (max([University Issuing Body])
       for seqnum in (1, 2, 3)
      )pvt

---

只需使用条件聚合：

select Sequence,
       max(case when seqnum = 1 then [University Issuing Body] end) as University_Issuing_Body_1,
       max(case when seqnum = 2 then [University Issuing Body] end) as University_Issuing_Body_2,
       max(case when seqnum = 3 then [University Issuing Body] end) as University_Issuing_Body_3
from (select pqj.*
             row_number() over (partition by [Sequence] order by [University Issuing Body]) as seqnum
      from [AB_DCU_IP_2018].[dbo].[PR_Q_Joined] pqj
     ) d
group by [University Issuing Body];

如果您确实想使用

pivot

，则没有理由定义

hdg

：

select [Sequence],
       [1] as [University Issuing Body_1], 
       [2] as [University Issuing Body_2], 
       [3] as [University Issuing Body_3]
from (select [Sequence], [University Issuing ,Body]
             row_number() over (partition by [Sequence] order by [University Issuing Body]) as seqnum
      from [AB_DCU_IP_2018].[dbo].[PR_Q_Joined]
     ) d
pivot (max([University Issuing Body])
       for seqnum in (1, 2, 3)
      )pvt

---

您正在使用hdg构建中间表，格式为大学发布机构

。但是你会在hdg格式为大学发行机构的地方提取出值。毫不奇怪，这与任何内容都不匹配——因此得到的是空值

只需在hdg的构造中加一个下划线：

select
 [Sequence]
,[University Issuing Body_1]
,[University Issuing Body_2]
,[University Issuing Body_3]
from (
    select
        [Sequence]
        ,[University Issuing Body]
        ,'University Issuing Body_' + cast(row_number() over(partition by [Sequence] order by [University Issuing Body]) as varchar(12)) as hdg
    from [AB_DCU_IP_2018].[dbo].[PR_Q_Joined]
    ) d
    pivot(
        max([University Issuing Body])
        for hdg in ([University Issuing Body_1], [University Issuing Body_2], [University Issuing Body_3])
        ) pvt

您正在使用hdg构建中间表，格式为大学发布机构
。但是你会在hdg格式为大学发行机构的地方提取出值。毫不奇怪，这与任何内容都不匹配——因此得到的是空值

只需在hdg的构造中加一个下划线：

select
 [Sequence]
,[University Issuing Body_1]
,[University Issuing Body_2]
,[University Issuing Body_3]
from (
    select
        [Sequence]
        ,[University Issuing Body]
        ,'University Issuing Body_' + cast(row_number() over(partition by [Sequence] order by [University Issuing Body]) as varchar(12)) as hdg
    from [AB_DCU_IP_2018].[dbo].[PR_Q_Joined]
    ) d
    pivot(
        max([University Issuing Body])
        for hdg in ([University Issuing Body_1], [University Issuing Body_2], [University Issuing Body_3])
        ) pvt

非常感谢你！真不敢相信我犯了多么愚蠢的错误。感谢您的回复：）非常感谢！真不敢相信我犯了多么愚蠢的错误。感谢您的回复：）谢谢！这真的很有帮助，谢谢！这真的很有帮助。