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Problème de requête SQL

CREATE TABLE #Garden (Id INT, Name VARCHAR(20))
INSERT INTO #Garden
SELECT 1, 'myGarden' UNION ALL
SELECT 2, 'yourGarden'

CREATE TABLE #Flowers (GardenId INT, Flower VARCHAR(20))
INSERT INTO #Flowers
SELECT  1, 'rose'  UNION ALL
SELECT  1, 'tulip'  UNION ALL
SELECT  2, 'thistle' 

DECLARE @ColList nvarchar(max)

SELECT @ColList = ISNULL(@ColList + ',','') + QUOTENAME('Flower' + CAST(ROW_NUMBER() OVER (ORDER BY (SELECT 0)) AS VARCHAR))
FROM #Flowers WHERE GardenId = (
SELECT TOP 1 GardenId
FROM #Flowers
ORDER BY COUNT(*) OVER (PARTITION BY GardenId) DESC

)

EXEC (N'
;WITH cte As
(
SELECT *, ''Flower'' + CAST(ROW_NUMBER() OVER (PARTITION BY GardenId ORDER BY (SELECT 0)) AS VARCHAR) RN
FROM #Flowers F
)
SELECT Name,' + @ColList + N'
FROM cte 
JOIN #Garden g ON g.Id = GardenId
PIVOT (MAX(Flower) FOR RN IN (' + @ColList + N')) Pvt')


DROP TABLE #Garden
DROP TABLE #Flowers

Retours

Name                 Flower1              Flower2
-------------------- -------------------- --------------------
myGarden             rose                 tulip
yourGarden           thistle              NULL