PL/SQL Return Cursor - plsql

Question

I am trying to define the PL/SQL function
CREATE OR REPLACE FUNCTION B2BOWNER.F_SSC_Page_Map_Select(
p_page_id IN B2BOWNER.SSC_Page_Map.PAGE_ID_NBR%TYPE,
p_page_type IN B2BOWNER.SSC_Page_Map.PAGE_TYPE%TYPE,
p_page_dcpn IN B2BOWNER.SSC_Page_Map.PAGE_DCPN%TYPE)
RETURN MAP_REC
AS
CURSOR MAP_CURSOR IS
SELECT *
FROM B2BOWNER.SSC_PAGE_MAP
WHERE PAGE_ID_NBR = p_page_id AND PAGE_TYPE = p_page_type;
MAP_REC MAP_CURSOR%ROWTYPE;
TABLE_DOES_NOT_EXIST exception;
PRAGMA EXCEPTION_INIT(TABLE_DOES_NOT_EXIST, -942); -- ORA-00942
BEGIN
FOR MAP_REC IN MAP_CURSOR
LOOP
System.out.println("ID: " + MAP_REC.PAGE_ID_NBR + " " + "TYPE: " + MAP_REC.PAGE_TYPE + " " + "DCPN: " + MAP_REC.PAGE_DCPN);
END LOOP;
RETURN MAP_REC;
EXCEPTION
WHEN TABLE_DOES_NOT_EXIST THEN
RETURN -1;
WHEN DUP_VAL_ON_INDEX THEN
RETURN -2;
WHEN INVALID_NUMBER THEN
RETURN -3;
WHEN OTHERS THEN
RETURN -4;
END F_SSC_Page_Map_Select;
SHOW ERRORS PROCEDURE B2BOWNER.F_SSC_Page_Map_Select;
GRANT EXECUTE ON B2BOWNER.F_SSC_Page_Map_Select TO B2B_USER_DBROLE;
and receive the following error
Warning: compiled but with compilation errors
No errors.
Grant complete.
[Warning] ORA-24344: success with compilation error
6/12 PLS-00320: the declaration of the type of this expression is incomplete or malformed
PL/SQL: Compilation unit analysis terminated
(1: 0): Warning: compiled but with compilation errors

Answer 1

A few things. First, the MAP_REC declared in the declaration section is not the same as the MAP_REC used in the cursor FOR loop. This was certainly surprising to me when I first encountered it but it's something we all have to get used to. To do what you're trying to do you'll need to either use the OPEN, FETCH, and CLOSE method of working with a cursor, or else copy the values from the cursor FOR loop variable to the 'declared' variable.
Secondly, you can't return a MAP_REC from this function as MAP_REC is declared inside the function and thus isn't known to the compiler when it processes the function definition. Best to use the specific table ROWTYPE.
Third, later in the code you have RETURN -1, etc, which won't work as a cursor %ROWTYPE variable. I suggest that instead of trying to return 'magic number' values to indicate specific failures you should simply let the exceptions propagate to the caller, who can then handle the exceptions as needed. That's why we have exceptions - to prevent having different error handling schemes for every single subroutine out there.
And finally: this is PL/SQL - we don't System.out.println here. :-)
A possible way to rewrite your code would be:
CREATE OR REPLACE FUNCTION B2BOWNER.F_SSC_Page_Map_Select(
p_page_id IN B2BOWNER.SSC_Page_Map.PAGE_ID_NBR%TYPE,
p_page_type IN B2BOWNER.SSC_Page_Map.PAGE_TYPE%TYPE,
p_page_dcpn IN B2BOWNER.SSC_Page_Map.PAGE_DCPN%TYPE)
RETURN B2BOWNER.SSC_PAGE_MAP%ROWTYPE
AS
CURSOR MAP_CURSOR IS
SELECT *
FROM B2BOWNER.SSC_PAGE_MAP
WHERE PAGE_ID_NBR = p_page_id AND
PAGE_TYPE = p_page_type;
MAP_REC B2BOWNER.SSC_PAGE_MAP%ROWTYPE;
bCursor_open BOOLEAN := FALSE;
BEGIN
OPEN MAP_CURSOR;
bCursor_open := TRUE;
LOOP
FETCH MAP_CURSOR
INTO MAP_REC;
EXIT WHEN MAP_CURSOR%NOT_FOUND;
DBMS_OUTPUT.PUT_LINE('ID: ' || MAP_REC.PAGE_ID_NBR || ' ' || 'TYPE: ' ||
MAP_REC.PAGE_TYPE || ' ' || 'DCPN: ' || MAP_REC.PAGE_DCPN);
END LOOP;
CLOSE MAP_CURSOR;
bCursor_open := FALSE;
RETURN MAP_REC;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Error in F_SSC_Page_Map_Select: ' || SQLCODE || ' ' ||
SQLERRM);
IF bCursor_open THEN
CLOSE MAP_CURSOR;
END IF;
RAISE;
END F_SSC_Page_Map_Select;
Best of luck.
Share and enjoy.