Sql server 使用group by将行动态转换为列
我正在寻找一个代码,可以使用GROUPBY将行转换为列,下面是我的表格和所需的输出 表格:Sql server 使用group by将行动态转换为列,sql-server,group-by,transpose,Sql Server,Group By,Transpose,我正在寻找一个代码,可以使用GROUPBY将行转换为列,下面是我的表格和所需的输出 表格: MR_ID | DR_ID --------|-------- MR_123 | 1 MR_123 | 3 MR_124 | 4 MR_124 | 5 MR_124 | 6 MR_125 | 0 渴望输出: MR_ID | DR_ID_1 | DR_ID_2 | DR_ID_3 --------|----------|----------|-----
MR_ID | DR_ID
--------|--------
MR_123 | 1
MR_123 | 3
MR_124 | 4
MR_124 | 5
MR_124 | 6
MR_125 | 0
渴望输出:
MR_ID | DR_ID_1 | DR_ID_2 | DR_ID_3
--------|----------|----------|---------
MR_123 | 1 | 2 | NULL
MR_124 | 4 | 5 | 6
MR_125 | 0 | NULL | NULL
这里我希望每个DR_ID的每个单独的列都有数字的增量,这应该是动态的 像这样试试:
DECLARE @mockup TABLE(MR_ID VARCHAR(10),DR_ID INT);
INSERT INTO @mockup VALUES
('MR_123',1)
,('MR_123',3)
,('MR_124',4)
,('MR_124',5)
,('MR_124',6)
,('MR_125',0);
SELECT p.*
FROM
(
SELECT *
,'DR_ID_' + CAST(ROW_NUMBER() OVER(PARTITION BY MR_ID ORDER BY DR_ID) AS VARCHAR(MAX)) AS columnName
FROM @mockup AS m
) AS t
PIVOT(MAX(DR_ID) FOR columnName IN(DR_ID_1,DR_ID_2,DR_ID_3,DR_ID_4)) AS p;
“动态列名”是用
行号()创建的。
您也可以使用动态sql查询
查询
declare @sql as varchar(max);
select @sql = 'select t.MR_ID, ' + stuff((
select distinct ', max(case t.[rn] when '
+ cast(t.[rn] as varchar(10)) + ' then t.[DR_ID] end)
[DR_ID' + cast(t.[rn] as varchar(10)) + ']'
from (
select [rn] = row_number()
over(partition by MR_ID order by DR_ID), *
from your_table_name
)t
for xml path('')
), 1, 2, '')
+ ' from (select [rn] = row_number() over(partition by MR_ID order by DR_ID), *
from your_table_name)t
group by t.[MR_ID];';
exec(@sql);
试试这个
create table #tmp (MR_ID varchar(50),DR_ID int)
insert into #tmp VALUES
('MR_123', 1),('MR_123', 3),('MR_124', 4),('MR_124', 5)
,('MR_124', 6),('MR_125', 0)
declare @DRCol varchar(50)
declare @Prefix varchar(20)='DR_'
;With CTE as
(
select *
,ROW_NUMBER()over(partition by MR_ID order by DR_ID)rn
from #tmp
)
select top 1
@DRCol=stuff((select ','+'['+@Prefix+cast(rn as varchar)+']'
from cte c1 where c.mr_id=c1.mr_id for xml path('')),1,1,'')
from cte c
where c.mr_id=(select top 1 mr_id from cte c1 order by rn desc)
declare @Sql varchar(2000)=''
set @Sql=' SELECT p.*
FROM
(
SELECT *
,'''+@Prefix+'''+ cast(ROW_NUMBER() OVER(PARTITION BY MR_ID ORDER BY DR_ID) as varchar(max)) columnName
FROM #tmp AS m
) AS t
PIVOT(MAX(DR_ID) FOR columnName IN('+@DRCol+')) AS p'
print @sql
exec(@sql)
drop table #tmp
您好,Ullas感谢您的回复,您能做些更多的帮助来理解它吗。此代码在38个以上的DR_ID上不起作用,因为它超过了变量存储限制。我收到这三个错误。1) “无法将默认值分配给局部变量。”2“必须声明标量变量“@Prefix”,3“关键字“order”附近的语法不正确”。@Jayank:我在查询中没有使用名为
@Prefix
的变量。1)在(CAST(ROW\u NUMBER
)之前缺少+
。”您缺少AS columnName
(在MAX之后))
和3)动态方法无法知道声明的表变量,因为它超出范围…@Shnugo,谢谢。我忘记了在动态sql中您不使用表变量。这是唯一的错误。其次,毫无疑问,我复制了您的sql的一部分。@KumarHarsh,我遇到了Order by的错误(order by rn)和“@Perfix”的标量变量错误我刚刚复制了脚本,运行时没有任何错误。抛出更多详细信息。我收到这三个错误。1)“无法为局部变量指定默认值。”2)“必须声明标量变量“@Prefix”,3)“关键字“order”附近的语法不正确。”,在子查询中--为@DRCol设置值时