Problem with return value of stored function

Question

Hi,
I've made a stored function that insert a new row in a table and return the primary key (see at the end of the message the function script).
In VS 2005 with Visual basic, using the designer, I've created a dataset containing a tableAdapter to be able to use the Pl/SQL function.
My problem is I can't get the proper return value. The VB code below works without error except that I get 0 as value.
What's wrong?
Cheers,
Sebastien
VB code
Dim myAddSession As New ICISDataSetTableAdapters.AddSessionTableAdapter
Dim intSessionId As Integer
intSessionId = myAddSession.ADD_SESSION(tbxUsername.Text, _
tempFolder.Substring(tempFolder.LastIndexOf("\") + 1), _
"toto", Environment.GetEnvironmentVariable("COMPUTERNAME"), _
myLevelAccess.icisUserId, myLevelAccess.levelId)
The debugger tells me that the ADD_SESSION function return value is Object.
add_session PL/SQL script:
CREATE OR REPLACE FUNCTION ICISSEC.add_session (
orausername IN icis_session.ora_user_name%TYPE,
ctxsessionid IN icis_session.ctx_session_id%TYPE,
ctxsessionname IN icis_session.ctx_session_name%TYPE,
ctxservername IN icis_session.ctx_server_name%TYPE,
icisuserid IN icis_session.icis_user_id%TYPE,
startlevelid IN icis_session.start_lvl_id%TYPE
RETURN icis_session.ICIS_SESSION_ID%TYPE
IS
tmpvar icis_session.ICIS_SESSION_ID%TYPE;
BEGIN
INSERT INTO icis_session
(ora_user_name, ctx_session_id, ctx_server_name,
icis_user_id, start_lvl_id, ctx_session_name
VALUES (orausername, ctxsessionid, ctxservername,
icisuserid, startlevelid, ctxsessionname
RETURNING icis_session_id
INTO tmpvar;
COMMIT;
RETURN tmpvar;
EXCEPTION
WHEN OTHERS
THEN
RAISE;
END add_session;

Answer 1

naama wrote:
that if a value is null to convert it to 0 ? . i mean in the part of the declaration of parameter
Nope, can't do that in the signature. You'll need to handle that by validating the passed parameters at the start of the function.
It's simple enough. In your case you might just as well test for NULL and fail the function like this:
    FUNCTION date_post_message(
            user_lock_in IN NUMBER,
            form_type_in IN NUMBER DEFAULT 0 ,
            date_in      IN DATE)
        RETURN BOOLEAN
    IS
        v_num NUMBER(1);
    BEGIN
        dbms_output.put_line('Value of parameters : user_lock_in : '||user_lock_in || ' : form_type_in : '||form_type_in||' : date_in : '||date_in );
        IF user_lock_in = 1 THEN
            RETURN FALSE;
        END IF;
        IF form_type_in IS NULL THEN
            RETURN FALSE;
        ELSIF form_type_in NOT IN (1,2) THEN
            RETURN FALSE;
        END IF;
        RETURN TRUE;
    EXCEPTION
    WHEN NO_DATA_FOUND THEN
        RETURN FALSE;
    END;In other use cases I would declare a local variable and process it like this:
        IF form_type_in IS NULL THEN
            l_form_type := 0;
        ELSE
             l_form_type := form_type_in;
        END IF;Obviously the code should use the local variable rather than the parameter.
Validating the values passed in parameters at the start of a function is good practice. If you really want to go to town, read about Design By Contract.
Cheers, APC
Edited by: APC on Nov 9, 2011 1:36 PM
Added example, as requested by OP