Question

I am trying to make an SQL Function that returns a nvarchar(MAX) string. The function uses a CTE recursive WITH statement. I can get all the parts to work correctly when they are not in the function but when I put them all together I get the following error:

Msg 208, Level 16, State 1, Line 1
Invalid object name ‘drillUp’.

The function itself does not give an error during “Compile” but only when it is run.
If I change the SET @RET to “TESTING…” instead of calling the SELECT statement it runs as expected.

I am fairly new to SQL and I am not sure what I am doing wrong. If anyone can give me some advice I would greatly appreciate it.

Thank you.

Joe

CREATE FUNCTION BuildName(@SUBTRAIT_ID int)
RETURNS nvarchar(MAX)
AS
BEGIN
DECLARE @RET nvarchar(MAX)
DECLARE @TEXTMODE nvarchar(50)
DECLARE @PARENTID int
DECLARE @CHECKDROPDOWN TABLE
(
    TextMode nvarchar(MAX),
    ParentId int
);

WITH drillUp(FullName, ParentId, depth) 
AS
(
    SELECT  
        SubValue,
        ParentId,
        0           
    FROM SubTrait
    WHERE Id = @SUBTRAIT_ID 
    UNION ALL
    SELECT                  
        child.SubValue + ' -> ' + drillUp.FullName,
        child.ParentId,
        drillUp.depth + 1
    FROM SubTrait child, drillUp
    WHERE drillUp.ParentId = child.Id 
)


INSERT @CHECKDROPDOWN 
SELECT TextMode, ParentId FROM SubTrait WHERE Id = @SUBTRAIT_ID

SET @TEXTMODE = (SELECT MAX(TextMode) FROM @CHECKDROPDOWN);
SET @PARENTID = (SELECT MAX(ParentId) FROM @CHECKDROPDOWN);

IF (@TEXTMODE != 'DropDown')
BEGIN
    SET @SUBTRAIT_ID = @PARENTID
END 

SET @RET = (
       SELECT FullName
       FROM drillUp du
       WHERE depth =(SELECT MAX(depth) FROM drillUp ) - 1
     )
--  SET @RET = 'TESTING...'

RETURN (@RET)

END;
GO


PRINT dbo.BuildName(77)

Answer 1

CTE’s are only valid to be used on the statement that follows his definition. So you should move your SET @RET to be next the definition of drillup:

CREATE FUNCTION BuildName(@SUBTRAIT_ID int)
RETURNS nvarchar(MAX)
AS
BEGIN
DECLARE @RET nvarchar(MAX)
DECLARE @TEXTMODE nvarchar(50)
DECLARE @PARENTID int
DECLARE @CHECKDROPDOWN TABLE
(
    TextMode nvarchar(MAX),
    ParentId int
);

INSERT @CHECKDROPDOWN 
SELECT TextMode, ParentId FROM SubTrait WHERE Id = 74

SET @TEXTMODE = (SELECT MAX(TextMode) FROM @CHECKDROPDOWN);
SET @PARENTID = (SELECT MAX(ParentId) FROM @CHECKDROPDOWN);

IF (@TEXTMODE != 'DropDown')
BEGIN
    SET @SUBTRAIT_ID = @PARENTID
END 

WITH drillUp(FullName, ParentId, depth) 
AS
(
    SELECT  
        SubValue,
        ParentId,
        0           
    FROM SubTrait
    WHERE Id = @SUBTRAIT_ID 
    UNION ALL
    SELECT                  
        child.SubValue + ' -> ' + drillUp.FullName,
        child.ParentId,
        drillUp.depth + 1
    FROM SubTrait child, drillUp
    WHERE drillUp.ParentId = child.Id 
)
SELECT @RET = (
       SELECT FullName
       FROM drillUp du
       WHERE depth =(SELECT MAX(depth) FROM drillUp ) - 1
     )
--  SET @RET = 'TESTING...'


RETURN (@RET)

END;
GO


PRINT dbo.BuildName(77)