我使用两个查询,第一个将一列分隔到两列并插入一个表,第二个查询(PIVOT)基于插入的表提取,
第一个查询,
SELECT A.MDDID, A.DeviceNumber,
Split.a.value('.', 'VARCHAR(100)') AS MetReading
FROM (
SELECT MDDID,DeviceNumber,
CAST ('<M>' + REPLACE(Httpstring, ':', '</M><M>') + '</M>' AS XML) AS MetReading
FROM [IOTDBV1].[dbo].[MDASDatas] E
Where E.MDDID = 49101
) AS A CROSS APPLY MetReading.nodes ('/M') AS Split(a);
第二次查询
SELECT * FROM
(
Select ID,MDDID,DeviceNumber,ReceivedDate
, ROW_NUMBER() OVER(PARTITION BY ID ORDER BY (SELECT 1)) AS ID2
, SPLT.MR.value('.','VARCHAR(MAX)') AS LIST FROM (
Select ID,MDDID,DeviceNumber,ReceivedDate
, CAST( '<M>'+REPLACE(MeterReading,',','</M><M>')+'</M>' AS XML) AS XML_MR
From [dbo].[PARSEMDASDatas] E
Where E.MeterReading is Not Null
)E
CROSS APPLY E.XML_MR.nodes('/M') AS SPLT(MR)
)A
PIVOT
(
MAX(LIST) FOR ID2 IN ([1],[2],[3],[4],[5],[6],[7],[8])
)PV
我希望根据第一个查询运行第二个查询,不需要表。 任何帮助将不胜感激。
最佳答案
你的问题不是很清楚...这是一个很好的例子,为什么你总是应该添加 MCVE ,包括 DDL、样本数据、自己的尝试、错误输出和预期输出。这次我给你做,下次自己尝试准备这样的MCVE...
如果我理解正确,您的源表包含一个 CSV 列,其中最多包含 8 个(最大值?)值。这可能会更容易解决,不需要将其分解为两个查询,不需要中间表,甚至不需要 PIVOT。
--create a mockup-table to simulate your situation (slightly shortened for brevity)
DECLARE @YourTable TABLE(ID INT,MDDID INT, DeviceNumber VARCHAR(100),MetReading VARCHAR(2000));
INSERT INTO @YourTable VALUES
(2,49101,'NKLDEVELOPMENT02','DCPL,981115,247484,9409') --the character code and some numbers
,(3,49101,'NKLDEVELOPMENT02','SPPL,,,,,,,,') --eigth empty commas
,(4,49101,'NKLDEVELOPMENT02','BLAH,,,999,,'); --A value somewhere in the middle
--cte 将返回表原样。唯一的区别是转换为 XML(你也这样做了)
WITH Splitted AS
(
SELECT ID
,MDDID
,DeviceNumber
,CAST('<x>' + REPLACE(MetReading,',','</x><x>') + '</x>' AS XML) AS Casted
FROM @YourTable t
)
SELECT s.ID
,s.MDDID
,s.DeviceNumber
,s.Casted.value('/x[1]','varchar(100)') AS [1]
,s.Casted.value('/x[2]','varchar(100)') AS [2]
,s.Casted.value('/x[3]','varchar(100)') AS [3]
,s.Casted.value('/x[4]','varchar(100)') AS [4]
,s.Casted.value('/x[5]','varchar(100)') AS [5]
,s.Casted.value('/x[6]','varchar(100)') AS [6]
,s.Casted.value('/x[7]','varchar(100)') AS [7]
,s.Casted.value('/x[8]','varchar(100)') AS [8]
FROM Splitted s;
结果
ID MDDID DeviceNumber 1 2 3 4 5 6 7 8
2 49101 NKLDEVELOPMENT02 DCPL 981115 247484 9409 NULL NULL NULL NULL
3 49101 NKLDEVELOPMENT02 SPPL
4 49101 NKLDEVELOPMENT02 BLAH 999 NULL NULL
简而言之:
每个 CSV 都被转换成类似于这样的 XML:
<x>DCPL</x>
<x>981115</x>
<x>247484</x>
<x>9409</x>
在 XPath 中使用位置谓词,我们可以调用第一个、第二个、第三个 <x>
很容易。
关于sql - 如何根据第一个查询运行第二个查询?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/56521386/