Want to pivot table. And generate dynamic SQL string and execute it - sql

Question

Create table script
CREATE TABLE #TableA
(
A VARCHAR(50),
Allocations INT,
Seats INT,
EndDate DATETIME
);
Insert table script
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');
Output of #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 |
I want the following query to be dynamic:
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;
Here I want dynamic string to generate EndDate column and execute that query and will have to give output.

Answer 1

You can use this script.
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
Result:
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