Executing cte expression in a dynamic sql - sql-server

Question

I have the following cte expression which I am try to run in a dynamic sql but I am getting invalid identifiers error in it:
DECLARE #t TABLE ( ID INT, V float, D DATE )
INSERT INTO #t
VALUES ( 1, 1.2, '2014-01-01' ),
( 1, 1.33, '2014-01-02' ),
( 1, 1.33, '2014-01-03' ),
( 1, 7, '2014-01-04' ),
( 2, 5, '2014-01-04' ),
( 2, 8, '2014-01-10' ),
( 2, 11, '2014-01-05' );
DECLARE #DealClauseString nvarchar(max)
SET #DealClauseString =';WITH filter
AS ( SELECT ID ,
D ,
V ,
ROW_NUMBER() OVER ( PARTITION BY ID ORDER BY D DESC ) AS RN
FROM #t where id =1
),
cte
AS ( SELECT ID ,
D ,
V ,
MIN(D) OVER ( PARTITION BY ID ORDER BY D ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING ) AS Min ,
MAX(D) OVER ( PARTITION BY ID ORDER BY D ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING ) AS Max
FROM filter
WHERE RN <= 2
)
SELECT c1.ID ,
c2.V - c1.V AS V
FROM cte c1
JOIN cte c2 ON c1.ID = c2.ID AND c1.D < c2.D
WHERE ( c1.D = c1.MIN OR c1.D = c1.MAX )
AND ( c2.D = c2.MIN OR c2.D = c2.MAX ) '
exec #DealClauseString
Any suggestions?
Also I was going to run this cte expression in a while loop. Are there any performance issue running cte expression in a loop?

Answer 1

Firstly, you can't use a table variable with dynamic sql, so you should use a #temp table instead, although this might just be relevant to your example code.
Secondly, if you are using dynamic sql, you either need to place the variable #DealClauseString in brackets or use sp_executesql, otherwise SQL Server assumes that you're calling a stored procedure.
CREATE TABLE #t ( ID INT, V FLOAT, D DATE )
INSERT INTO #t
VALUES ( 1, 1.2, '2014-01-01' ),
( 1, 1.33, '2014-01-02' ),
( 1, 1.33, '2014-01-03' ),
( 1, 7, '2014-01-04' ),
( 2, 5, '2014-01-04' ),
( 2, 8, '2014-01-10' ),
( 2, 11, '2014-01-05' );
DECLARE #DealClauseString NVARCHAR(MAX)
SET #DealClauseString = ';WITH filter
AS ( SELECT ID ,
D ,
V ,
ROW_NUMBER() OVER ( PARTITION BY ID ORDER BY D DESC ) AS RN
FROM #t where id =1
),
cte
AS ( SELECT ID ,
D ,
V ,
MIN(D) OVER ( PARTITION BY ID ORDER BY D ROWS
BETWEEN UNBOUNDED PRECEDING
AND UNBOUNDED FOLLOWING ) AS Min ,
MAX(D) OVER ( PARTITION BY ID ORDER BY D ROWS
BETWEEN UNBOUNDED PRECEDING AND
UNBOUNDED FOLLOWING ) AS Max
FROM filter
WHERE RN <= 2
)
SELECT c1.ID ,
c2.V - c1.V AS V
FROM cte c1
JOIN cte c2 ON c1.ID = c2.ID AND c1.D < c2.D
WHERE ( c1.D = c1.MIN OR c1.D = c1.MAX )
AND ( c2.D = c2.MIN OR c2.D = c2.MAX ) '
EXEC (#DealClauseString)
Results:
ID V
1 5.67