Incompatible object type when create and alter a table value function in SQL

Question

I'm getting the below error for the given function.

Msg 2010, Level 16, State 1, Procedure GetTableFromDelimitedValues, Line 2 Cannot perform alter on 'dbo.GetTableFromDelimitedValues' because it is an incompatible object type.

IF NOT EXISTS(SELECT 1 FROM sys.objects 
              WHERE object_id = OBJECT_ID('[GetTableFromDelimitedValues]'))
BEGIN
   EXECUTE('CREATE FUNCTION [dbo].[GetTableFromDelimitedValues](@input varchar(max),
       @delimiter char(1) = ",")) RETURNS @Result TABLE (
       Value nvarchar(4000)) AS BEGIN RETURN END')
END
GO


ALTER FUNCTION [dbo].[GetTableFromDelimitedValues](
       @input varchar(max),
       @delimiter char(1) = ',')
RETURNS @Result TABLE
(
       Value nvarchar(4000)
)
AS
BEGIN
    DECLARE @position int;
    DECLARE @column nvarchar(4000);

    WHILE LEN(@input) > 0
    BEGIN
        SET @position = CHARINDEX(@delimiter, @input);
        IF (@position < 0) OR (@position IS NULL)
        BEGIN
            SET @position = 0;
        END

        IF @position > 0 
        BEGIN
            SET @column = SUBSTRING(@input, 1, @position - 1);
            SET @input = SUBSTRING(@input, @position + 1, LEN(@input) - @position)
        END
        ELSE
        BEGIN
            SET @column = @input;
            SET @input = '';
        END 

        INSERT @Result (Value) 
        SELECT @column;
    END;

    RETURN;                
END
GO

Can someone please help me to get the compatible type by fixing the function?

Answer 1

You need to DROP and CREATE the function in this particular context

Since there is change in function return type, we must drop then recreate the function.

There are three types of functions,

• Scalar
• Inline table valued and
• Multi Statement

ALTER cannot be used to change the function type.