按列和多行分组为一行多列

问题描述

正如我在评论中所提到的，这里您需要的是PIVOT或交叉标签；我更喜欢后者，所以我将要使用的东西。

对此的非动态解决方案如下：

WITH RNs AS(
    SELECT WorkOrder,
           TestType,
           Result,
           ROW_NUMBER() OVER (PARTITION BY WorkOrder, TestType ORDER BY (SELECT NULL)) AS RN --ORDER BY should be your ID/always ascending column
    FROM dbo.Result)
SELECT WorkOrder,
       TestType,
       MAX(CASE RN WHEN 1 THEN Result END) AS Result1,
       MAX(CASE RN WHEN 2 THEN Result END) AS Result2,
       MAX(CASE RN WHEN 3 THEN Result END) AS Result3
FROM RNs R
GROUP BY WorkOrder,
         TestType;

但是，问题在于这会将您“锁定”到3个结果中，但是您建议存在不确定数量的结果。因此，您需要一个动态的解决方案。

以下将最多处理100个结果。如果你需要更多的列比超过，再加入更多的CROSS JOINs到N的CTETally。结果是这样的（非常混乱）。

DECLARE @sql nvarchar(MAX),
        @CRLF nchar(2) = NCHAR(13) + NCHAR(10),
        @MaxTally int;

SELECT @MaxTally = MAX(C)
FROM (SELECT COUNT(*) AS C
      FROM dbo.Result
      GROUP BY WorkOrder,
               TestType) R;

WITH N AS(
    SELECT N
    FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL))N(N)),
Tally AS(
    SELECT TOP (@MaxTally) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS I
    FROM N N1, N N2) --100 rows, add more Ns for more rows
SELECT @sql = N'WITH RNs AS(' + @CRLF +
              N'    SELECT WorkOrder,' + @CRLF +
              N'           TestType,' + @CRLF +
              N'           Result,' + @CRLF +
              N'           ROW_NUMBER() OVER (PARTITION BY WorkOrder, TestType ORDER BY (SELECT NULL)) AS RN --ORDER BY should be your ID/always ascending column' + @CRLF +
              N'    FROM dbo.Result)' + @CRLF +
              N'SELECT WorkOrder,' + @CRLF +
              N'       TestType,' + @CRLF +
              --Using FOR XML PATH due to not kNowing sql Server version
              STUFF((SELECT N',' + @CRLF +
                            CONCAT(N'       MAX(CASE RN WHEN ',T.I,N' THEN Result END) AS Result',T.I)
                     FROM Tally T
                     ORDER BY T.I ASC
                     FOR XML PATH(N''),TYPE).value('(./text())[1]','nvarchar(MAX)'),1,3,N'') + @CRLF +
              N'FROM RNs R' + @CRLF +
              N'GROUP BY WorkOrder,' + @CRLF +
              N'         TestType;';

PRINT @sql; --Your best friend.

EXEC sys.sp_executesql @sql;

解决方法

请帮我这个：

我想按列TestType分组，但如果它们具有相同的TestType，则应将Result拆分为colunms

CREATE TABLE Result(WorkOrder varchar(10),TestType varchar(20),Result decimal(10,2));
INSERT INTO Result (WorkOrder,TestType,Result) VALUES 
('HP19002316','VitaminA',10.3),('HP19002316',11.3),12.3),'VitaminB',13.4),14.4),'VitaminC',15.5),'VitaminD',17.0)

我希望SQL以这种格式返回数据

WorkOrder       TestType        Result1   Result2  Result3 
==========================================================
HP19002316      VitaminA        10.3        11.3    12.3    
HP19002316      VitaminB        13.4        14.4    NULL
HP19002316      VitaminC        15.5        NULL    NULL
HP19002316      VitaminD        17.0        NULL    NULL

Result＃列应该是动态的，因为每个TestType都有很多结果

sql sql