查询将一列中的2行合并为1列,每列2列

时间:2015-07-09 07:07:57

标签: sql tsql sql-server-2008-r2

我需要处理一个查询字符串并从中创建记录。

最初格式是这种格式的转义字符串:

relativeFilePath1^relativeFilePath2^relativeFilePath3^relativeFilePath4

使用%5E转义^字符。用于在此位置拆分字符串,创建临时表,在其中插入所有内容并从那里触发插入。

DECLARE @SplittetList TABLE(ID int Identity(1,1), fPath nvarchar(max));
INSERT INTO @SplittetList SELECT * FROM Schema.fnSplit('relativeFilePath1%5ErelativeFilePath2%5ErelativeFilePath3%5ErelativeFilePath4', '%5E')
--additional processing

现在格式即将更改,以便在每个文件路径之后,还有该文件的其他元数据字段,也用^字符分隔。如果我现在拆分这个我得到这样的结果:

ID |  fPath
---------------------
1  |  relativeFilePath1
2  |  metadata1
3  |  relativeFilePath2
4  |  metadata2
5  |  relativeFilePath3
6  |  metadata3
n  |  ...

如何转换此列表,以便结果是这种格式的一组数据:

filepath           |     metadata
----------------------------------
relativeFilePath1  |     metadata1
relativeFilePath2  |     metadata2
relativeFilePath3  |     metadata3
...

1 个答案:

答案 0 :(得分:1)

DECLARE @Data table
(
    ID int identity(1,1),
    fPath nvarchar(max)
)

insert @Data values
('relativeFilePath1'),('metadata1'),('relativeFilePath2'),('metadata2'),('relativeFilePath3'),('metadata3')

-- ROW_NUMBER to ensure the ID is continuous
;with data as 
(
    select *, 
        (ROW_NUMBER() OVER (ORDER BY Id)+1)/2 as grp, 
        (ROW_NUMBER() OVER (ORDER BY Id)+1)%2 as columnno 
    from @Data
)
-- Subquery verison
select 
    (select fPath from data where grp = d.grp and columnno = 0) as filepath, 
    (select fPath from data where grp = d.grp and columnno = 1) as metadata
from data d group by grp

-- Inner join version
--select a.fPath, b.fPath from data a inner join data b on a.grp = b.grp
--where a.columnno = 0 and b.columnno = 1
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