Question

I have a database with multiple questionnaires, each questionnaire has related (multiplechoice) questions, and each question has related answers.

I’m trying to create a stored procedure that will delete all questions and related answers with only the ID of the questionnaire.
My stored procedure looks like this:

ALTER PROCEDURE [dbo].[DeleteQuestionnnaire] 

    @EnqueteID bigint
AS

BEGIN
    SET NOCOUNT ON

    DECLARE @QID bigint

    DECLARE questionCursor CURSOR FOR
        SELECT ID FROM questions WHERE EnqueteID = @EnqueteID

    OPEN questionCursor;

    FETCH questionCursor INTO @QID  

    WHILE(@@fetch_status=0)
    BEGIN

    -- this is not working correct, the related answers are NOT being deleted

        FETCH questionCursor INTO @QID
        DELETE FROM answers WHERE QuestionID=@QID

    END

    CLOSE questionCursor

        --  this works fine, the questions are being deleted
    DELETE FROM questions WHERE EnqueteID=@EnqueteID

END

the related questions are being deleted but the related answers not, so I’m doing something wrong in my loop, is there anybody out there who sees what it is?

Thanks in advance

Answer 1

Your cursor is slightly odd, in that FETCH NEXT is usually the last statement in the loop (see the example from the documentation), so in fact the first value you fetch is immediately replaced by the second one. Adding some PRINT statements into the cursor to check the current value of @QID would show this.

But the real answer is not to use a cursor at all, it’s unnecessary here:

delete from dbo.answers where questionid in (
    select questionid from dbo.questions where EnqueteID = @EnqueteID
)
delete from dbo.questions where EnqueteID = @EnqueteID