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Comment utiliser une instruction CTE dans une fonction table dans SQL Server

J'ai compris que certaines versions de Microsoft OLE DB Provider for SQL Server (principalement sous Windows XP) ne prennent pas en charge l'instruction WITH. J'ai donc décidé de déplacer mon SQL dans une fonction table et l'appeler à partir de mon application. Maintenant, je suis bloqué. Comment dois-je utiliser le INSERT INTO instruction avec WITH? Voici le code que j'ai fourni jusqu'à présent, mais SQL Server ne l'aime pas ... :-(

CREATE FUNCTION GetDistributionTable 
(
    @IntID int,
    @TestID int,
    @DateFrom datetime,
    @DateTo datetime
)
RETURNS 
@Table_Var TABLE 
(
    [Count] int, 
    Result float
)
AS
BEGIN
INSERT INTO @Table_Var ([Count], Result) WITH T(Result)
     AS (SELECT ROUND(Result - AVG(Result) OVER(), 1)
         FROM RawResults WHERE IntID = @IntID AND DBTestID = @TestID AND Time >= @DateFrom AND Time <= @DateTo)
SELECT COUNT(*) AS [Count],
       Result
FROM   T
GROUP  BY Result

    RETURN 
END
GO
sql-serversql-server-2008-r2common-table-expression
32
iMan Biglari

Vous pouvez omettre la CTE (instruction WITH) et créer à la place une fonction de valeur de table en ligne qui utilise la sous-requête:

CREATE FUNCTION GetDistributionTable 
(
    @IntID int,
    @TestID int,
    @DateFrom datetime,
    @DateTo datetime
)
RETURNS TABLE
AS
RETURN  
(
    SELECT  COUNT(*) AS [Count],
            Result
    FROM    (
                 SELECT ROUND(Result - AVG(Result) OVER(), 1) Result
                 FROM   RawResults 
                 WHERE  IntID = @IntID 
                 AND    DBTestID = @TestID 
                 AND    Time >= @DateFrom 
                 AND Time <= @DateTo    
    ) t
    GROUP  BY 
            Result
)
GO

La syntaxe du CTE dans la fonction de valeur de table serait:

CREATE FUNCTION GetDistributionTable 
(
    @IntID int,
    @TestID int,
    @DateFrom datetime,
    @DateTo datetime
)
RETURNS TABLE
AS
RETURN  
(
    WITH cte AS
    (
        SELECT ROUND(Result - AVG(Result) OVER(), 1) Result
        FROM   RawResults 
        WHERE  IntID = @IntID 
        AND    DBTestID = @TestID 
        AND    Time >= @DateFrom 
        AND Time <= @DateTo    
    )

    SELECT  COUNT(*) AS [Count],
            Result
    FROM    cte
    GROUP  BY 
            Result
)
GO

Votre exemple semble utiliser un TVF multi-instructions (insérer et sélectionner), lorsque vous avez le choix, essayez d'utiliser le TVF en ligne car le TVF multi-instructions peut empêcher l'optimiseur de requêtes dans le choix d'un meilleur plan d'exécution (différence de performance expliquée ici)

45
Ivan G

COMME ÇA..

CREATE FUNCTION GetDistributionTable 
(
    @IntID int,
    @TestID int,
    @DateFrom datetime,
    @DateTo datetime
)
RETURNS 
@Table_Var TABLE 
(
    [Count] int, 
    Result float
)
AS
BEGIN
  WITH T 
    AS (    
        select Ticket_Id,COUNT(1) Result from 
        Customer_Survey
        group by MemberID,SiteId,Ticket_Id
   )
  INSERT INTO @Table_Var ([Count], Result)
  SELECT COUNT(*) AS [Count],
       Result
  FROM   T
  GROUP  BY Result
  RETURN 
END
GO
16
Ram Das
CTE with if else in UDF 

USE [SchoolDB]
GO

/****** Object:  UserDefinedFunction [dbo].[GetDistributionTable]    Script Date: 24-08-2019 05:17:55 PM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO





alter  FUNCTION [dbo].[GetDistributionTable] 
(
   @DepartmentName varchar(50) = 'Production'
)
RETURNS 
@Table_Var TABLE 
(   NUM int IDENTITY(1,1),
    [ParentEmployeeKey] int, 
    Result float
)
AS
BEGIN
Declare @Table_Vars table
(
    [ParentEmployeeKey] int, 
    Result float
);
insert into @Table_Vars([ParentEmployeeKey])
select COUNT(1) Result from 
        [SchoolDB].[dbo].[DimEmployee] where DepartmentName = @DepartmentName
if(@@rowcount >0)
begin
WITH T 
    AS (    
        select [ParentEmployeeKey],COUNT(1) Result from 
        [SchoolDB].[dbo].[DimEmployee] where DepartmentName = @DepartmentName
        group by [ParentEmployeeKey]
   )
  INSERT INTO @Table_Var ([ParentEmployeeKey], Result)
  SELECT COUNT(*) AS [Count],
       Result
  FROM   T
  GROUP  BY Result
end
else

 WITH T 
    AS (    
        select [ParentEmployeeKey],COUNT(1) Result from 
        [SchoolDB].[dbo].[DimEmployee] where DepartmentName = @DepartmentName
        group by [ParentEmployeeKey]
   )
  INSERT INTO @Table_Var ([ParentEmployeeKey], Result)
  SELECT COUNT(*) AS [Count],
       Result
  FROM   T
  GROUP  BY Result
  RETURN 
END



GO
0
Jai K