想要数据透视表。而生成动态SQL字符串，执行它

Question

创建表脚本

CREATE TABLE #TableA 
(
    A   VARCHAR(50), 
    Allocations INT, 
    Seats  INT, 
    EndDate  DATETIME 
); 

插入表脚本

INSERT INTO #TableA 
VALUES  ('ABC',450,23,'2017-10-05'), 
      ('ABC',23,765,'2017-05-01'), 
      ('PQR',54,34,'2017-07-04'), 
      ('ABC',234,45,'2017-11-27'), 
      ('PQR',987,76,'2017-03-05'), 
      ('ABC',76,65,'2017-02-23'), 
      ('PQR',89,324,'2017-08-14'), 
      ('ABC',45,34,'2017-07-13'); 

输出的#TableA

A | Allocations | Seats | EndDate     | 
-----+---------------+---------+-----------------------------+ 
ABC | 450   | 23 | 2017-10-05 00:00:00.000 | 
ABC | 23   | 765 | 2017-05-01 00:00:00.000 | 
PQR | 54   | 34 | 2017-07-04 00:00:00.000 | 
ABC | 234   | 45 | 2017-11-27 00:00:00.000 | 
PQR | 987   | 76 | 2017-03-05 00:00:00.000 | 
ABC | 76   | 65 | 2017-02-23 00:00:00.000 | 
PQR | 89   | 324 | 2017-08-14 00:00:00.000 | 
ABC | 45   | 34 | 2017-07-13 00:00:00.000 | 

我想下面的查询是动态的：

WITH T AS 
(
    SELECT 
     A, thing, priority, value, d 
    FROM 
     #TableA 
    CROSS APPLY (VALUES(CAST(EndDate AS DATE)))D(d) 
    CROSS APPLY (VALUES(1, 'A', NULL), 
         (2, 'Allocations', Allocations), 
         (3, 'Seats', Seats)) V(priority, thing, value) 
) 
SELECT 
    thing, 
    case when thing = 'A' THEN A ELSE CAST(ISNULL([2017-02-23],0) AS VARCHAR(50)) END AS [2017-02-23], 
    case when thing = 'A' THEN A ELSE CAST(ISNULL([2017-03-05],0) AS VARCHAR(50)) END AS [2017-03-05], 
    case when thing = 'A' THEN A ELSE CAST(ISNULL([2017-05-01],0) AS VARCHAR(50)) END AS [2017-05-01], 
    case when thing = 'A' THEN A ELSE CAST(ISNULL([2017-07-04],0) AS VARCHAR(50)) END AS [2017-07-04], 
    case when thing = 'A' THEN A ELSE CAST(ISNULL([2017-07-13],0) AS VARCHAR(50)) END AS [2017-07-13], 
    case when thing = 'A' THEN A ELSE CAST(ISNULL([2017-08-14],0) AS VARCHAR(50)) END AS [2017-08-14], 
    case when thing = 'A' THEN A ELSE CAST(ISNULL([2017-10-05],0) AS VARCHAR(50)) END AS [2017-10-05], 
    case when thing = 'A' THEN A ELSE CAST(ISNULL([2017-11-27],0) AS VARCHAR(50)) END AS [2017-11-27] 
FROM 
    T 
PIVOT 
    (SUM(value) FOR d in (
          [2017-02-23], 
          [2017-03-05], 
          [2017-05-01], 
          [2017-07-04], 
          [2017-07-13], 
          [2017-08-14], 
          [2017-10-05], 
          [2017-11-27])) P 
ORDER BY A, priority; 

这里我想要动态字符串来生成EndDate列并执行该查询，并且必须给出输出。

Answer 1

您可以使用此脚本。

DECLARE @ColumnNamesSelect NVARCHAR(MAX) ='' 
SELECT @ColumnNamesSelect = @ColumnNamesSelect + ', case when thing = ''A'' THEN A ELSE CAST(ISNULL(' + QUOTENAME (ColName) + ',0) AS VARCHAR(50)) END AS ' + QUOTENAME (ColName ) 
FROM (SELECT DISTINCT CONVERT(VARCHAR(10),EndDate,120) ColName FROM #TableA) AS T 
SET @ColumnNamesSelect = STUFF(@ColumnNamesSelect,1,1,'') 

DECLARE @ColumnNamesWhere NVARCHAR(MAX) ='' 
SELECT @ColumnNamesWhere = @ColumnNamesWhere + ', ' + QUOTENAME (ColName) 
FROM (SELECT DISTINCT CONVERT(VARCHAR(10),EndDate,120) ColName FROM #TableA) AS T 
SET @ColumnNamesWhere = STUFF(@ColumnNamesWhere,1,1,'') 


DECLARE @SqlText NVARCHAR(MAX) = 
'WITH T 
    AS (SELECT A, 
       thing, 
       priority, 
       value, 
       d 
     FROM #TableA 
       CROSS APPLY (VALUES(CAST(EndDate AS DATE)))D(d) 
       CROSS APPLY (VALUES(1, ''A'', NULL), 
            (2, ''Allocations'', Allocations), 
            (3, ''Seats'', Seats)) V(priority, thing, value)) 
SELECT thing, ' + @ColumnNamesSelect + 
' FROM T 
     PIVOT (SUM(value) FOR d IN (' + @ColumnNamesWhere + ')) P' 
+' ORDER BY A, priority;' 
EXEC sp_executesql @SqlText 

print @SqlText 

DROP TABLE #TableA 

结果：

thing  2017-02-23           2017-03-05           2017-05-01           2017-07-04           2017-07-13           2017-08-14           2017-10-05           2017-11-27 
----------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- 
A   ABC            ABC            ABC            ABC            ABC            ABC            ABC            ABC 
Allocations 76             0             23             0             45             0             450            234 
Seats  65             0             765            0             34             0             23             45 
A   PQR            PQR            PQR            PQR            PQR            PQR            PQR            PQR 
Allocations 0             987            0             54             0             89             0             0 
Seats  0             76             0             34             0             324            0             0