Value does not apply to variable in SQL Anywhere

Question

when I try to execute this function I get a error. When I execute the command without a function and without using variables it works, therefore I think the value does not apply to my variable, the declaration or the setting of variable does not work. It doesn't matter if I use SELECT or SET to set the variable, I get the same error which literally just says: The command could not be executed.

CREATE FUNCTION ueberpruefe_kfz_status (@kennzeichen CHAR(15))
RETURNS VARCHAR
AS
BEGIN
    DECLARE @ergebnis VARCHAR

    SELECT STATUS
    INTO @ergebnis
    FROM KFZ
    WHERE KENNZEICHEN = @kennzeichen

    RETURN @ergebnis
END

Here are some screenshots of the structure, sample data and the error: https://picload.org/folder/ldpwa.html

Answer 1

As per your table structure seen in the image, it seems like your column STATUS is of type CHAR. Try to Change your function return type from VARCHAR to CHAR like-

RETURNS CHAR

And type of variable @ergebnis to CHAR like-

DECLARE @ergebnis CHAR

You may specify length along with CHAR, like CHAR(15), which should be greater than or equal to the length of your STATUS column.