如何解决动态取消透视和拆分列SQL Server 2012
您只需要在执行以下操作后拆分列UNPIVOT：
WITH UnpiVoted
AS
(
SELECT region, lob, columns, value
FROM Regions
UNPIVOT
(
columns
FOR value IN([GWP 2013] , [GWP 2014] ,
[LR 2013] , [LR 2014] ,
[GWP 2015], [LR 2015])
) AS u
)
SELECT
region,
lob,
columns,
CAST(CASE WHEN value LIKE 'GWP%' THEN REPLACE(value,'GWP ', '')
WHEN value LIKE 'LR%' THEN REPLACE(value,'LR ', '')
END AS INT) AS Year,
CASE WHEN value LIKE 'GWP%' THEN 'GWP'
WHEN value LIKE 'LR%' THEN 'LR'
END AS Metrics
FROM UnpiVoted;
然后，您当然应该动态地执行此操作，以避免手动列出列并动态地进行操作：
DECLARE @cols AS NVARCHAR(MAX);
DECLARE @query AS NVARCHAR(MAX);
select @cols = STUFF((SELECT distinct ',' +
QUOTENAME(column_name)
FROM information_schema.columns
WHERE table_name = 'Regions'
AND COLUMN_NAME <> 'Region'
AND COLUMN_NAME <> 'LOB'
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
, 1, 1, '');
SELECT @query = 'WITH UnpiVoted
AS
(
SELECT region, lob, columns, value
FROM Regions
UNPIVOT
(
columns
FOR value IN('+ @cols + ')
) AS u
)
SELECT
region,
lob,
columns,
CAST(CASE WHEN value LIKE ''GWP%'' THEN REPLACE(value,''GWP '', '''')
WHEN value LIKE ''LR%'' THEN REPLACE(value,''LR '', '''')
END AS INT) AS Year,
CASE WHEN value LIKE ''GWP%'' THEN ''GWP''
WHEN value LIKE ''LR%'' THEN ''LR''
END AS Metrics
FROM UnpiVoted';
EXECUTE(@query);
假设以下情况，这应该可以正常工作：
- 所有列
[GWP 2013] , [GWP 2014] , [LR 2013] , [LR 2014] , [GWP 2015], [LR 2015], ... etc的格式都相同（GWP或LR，然后是空格，然后是年份，以及 -
所有列都是相同的数据类型
int或十进制数，如果数据类型不相同，则应在执行之前unpivot将它们全部转换为一种数据类型，否则会出现错误。
这将为您提供：
| region | lob | columns | Year | Metrics |
|--------|---------|----------|------|---------|
| north | Workers | 38902.5 | 2013 | GWP |
| north | Workers | 37972404 | 2014 | GWP |
| north | Workers | 70 | 2015 | GWP |
| north | Workers | 89 | 2013 | LR |
| north | Workers | 82 | 2014 | LR |
| north | Workers | 80 | 2015 | LR |
我曾经FOR XML PATH('') ..将所有值列表串联在一个字符串中，这是sql
Server的一种解决方法。的值@cols将是字符串：[GWP 2013], [GWP 2014], ...。
如果您的字段数据类型不同，则必须对所有将在锚点查询中未透视的列进行强制转换，然后再执行UNPVOT以下操作：
SELECT @query = 'WITH UnpiVoted
AS
(
SELECT region, lob, columns, value
FROM
(
SELECT
region,
lob,
CAST([GWP 2013] AS DECIMAL(10,2)) AS [GWP 2013],
CAST([GWP 2014] AS DECIMAL(10,2)) AS [GWP 2014],
... etc
FROM Regions
) AS t
UNPIVOT
(
columns
FOR value IN('+ @cols + ')
) AS u
)
SELECT
region,
lob,
columns,
CAST(CASE WHEN value LIKE ''GWP%'' THEN REPLACE(value,''GWP '', '''')
WHEN value LIKE ''LR%'' THEN REPLACE(value,''LR '', '''')
END AS INT) AS Year,
CASE WHEN value LIKE ''GWP%'' THEN ''GWP''
WHEN value LIKE ''LR%'' THEN ''LR''
END AS Metrics
FROM UnpiVoted';
如果发现很难手动为所有列编写类型转换，则可以动态生成它并附加它，例如：
DECLARE @colsCasted AS NVARCHAR(MAX);
select @colsCasted = STUFF((SELECT distinct ',' +
'CAST(' + QUOTENAME(column_name) + 'AS DECIMAL(10,2)) AS ' + QUOTENAME(column_name)
FROM information_schema.columns
WHERE table_name = 'Regions'
AND COLUMN_NAME <> 'Region'
AND COLUMN_NAME <> 'LOB'
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
, 1, 1, '');
然后在动态查询中将该值附加到它：
SELECT @query = 'WITH UnpiVoted
AS
(
SELECT region, lob, columns, value
FROM
(
SELECT region, lob,
' + @colsCasted + '
FROM Regions
) AS t
UNPIVOT
(
columns
FOR value IN('+ @cols + ')
) AS u
)
SELECT
region,
lob,
columns,
CAST(CASE WHEN value LIKE ''GWP%'' THEN REPLACE(value,''GWP '', '''')
WHEN value LIKE ''LR%'' THEN REPLACE(value,''LR '', '''')
END AS INT) AS Year,
CASE WHEN value LIKE ''GWP%'' THEN ''GWP''
WHEN value LIKE ''LR%'' THEN ''LR''
END AS Metrics
FROM UnpiVoted';
EXECUTE(@query);
解决方法
我有一个表作为MarketOutput有20列
[Region] [LOB] [GWP 2013] [GWP 2014] [LR 2013] [LR 2014]
-------------------------------------------------------------
North Workers 38902.50 37,972,404 89 82
我想将列动态更改为行。Region和LOB是固定列，[GWP 2013]，[GWP 2014]，[LR 2013]，[LR 2014]是动态列。
对于明年[GWP 2015]，[LR 2015]
我想取消透视该列，并将[GWP 2014]拆分为两列[GWP]，[2014]。
输出应该像
Region [LOB] [Metrics] [Year] [Value]
--------------------------------------------------
North Workers GWP 2013 38902.50
North Workers GWP 2014 37,404
North Workers LR 2013 89
North Workers LR 2014 82
你能建议如何做到吗？
我是SQL Server的新手
我也想每次使用动态列表将输出插入到新表中
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