How to execute dynamic sql into cursor in Oracle? - sql

Question

I have problem with execute dynamic sql statement into sys_refcursor in my stored procedure.
I have looked in documentation and I think that I build my procedure properly, but I still do not know why error occurs.
Please look below, what I created:
CREATE TABLE REKOM_CROSS_PROM (
LINIA_PROD VARCHAR2(20),
ID_REKOM_OFERTA VARCHAR2(20),
PRICE NUMBER,
MAX_PRICE NUMBER
);
/
CREATE OR REPLACE TYPE prodType AS OBJECT (
p_line VARCHAR2(20)
,p_price NUMBER
);
/
CREATE OR REPLACE TYPE prodTypeList IS TABLE OF prodType;
/
CREATE OR REPLACE PROCEDURE my_proc (prodLines IN prodTypeList ,rekom OUT SYS_REFCURSOR)
IS
v_pLine VARCHAR2(20);
v_query VARCHAR2(4000);
BEGIN
v_query := 'SELECT ID_REKOM_OFERTA FROM REKOM_CROSS_PROM WHERE
LINIA_PROD=NULL';
FOR i IN 1 .. prodLines.COUNT
LOOP
v_pLine := prodLines(i).p_line;
v_query := v_query || ' UNION ALL SELECT ID_REKOM_OFERTA FROM
REKOM_CROSS_PROM WHERE LINIA_PROD=''' || v_pLine || '''';
END LOOP;
OPEN rekom FOR v_query;
END my_proc;
/
And when I want to call the procedure, error occur.
set serveroutput on
declare
type1 prodTypeList := prodTypeList(prodType('test1',1), prodType('test2', 20));
rc SYS_REFCURSOR;
row varchar2(200);
BEGIN
MY_PROC(type1, rc);
fetch rc into row;
while (rc%found) loop
dbms_output.put_line(row);
end loop;
close rc;
end;
I get the message:
ORA-20000: ORU-10027: buffer overflow, limit of 1000000 bytes
*Cause: The stored procedure 'raise_application_error'
was called which causes this error to be generated.
*Action: Correct the problem as described in the error message or contact
the application administrator or DBA for more information.
Can sombody help me to resolve the problem?

Answer 1

You have an infinite loop. That means you're calling dbms_output.put_line forever - or until it runs out of buffer space, and throws that exception.
BEGIN
MY_PROC(type1, rc);
-- fetch first row from result set
fetch rc into row;
-- check if last fetch found something - always true
while (rc%found) loop
dbms_output.put_line(row);
end loop;
close rc;
end;
Every time around the loop you're checking the result of that first fetch, which stays true (assuming there is any data). You need to fetch each time round the loop:
BEGIN
MY_PROC(type1, rc);
-- fetch first row from result set
fetch rc into row;
-- check if last fetch found something
while (rc%found) loop
dbms_output.put_line(row);
-- fetch next row from result set
fetch rc into row;
end loop;
close rc;
end;
Or perhaps more commonly, only fetch inside the loop, and stop when nothing is found, using %notfound rather than %found:
BEGIN
MY_PROC(type1, rc);
loop
-- fetch row from result set
fetch rc into row;
-- check if last fetch found something
exit when rc%notfound;
dbms_output.put_line(row);
end loop;
close rc;
end;
Not related to your current issue, but the predicate WHERE LINIA_PROD=NULL is never true; null isn't equal to (or not equal to) anything else. You need to use WHERE LINIA_PROD IS NULL instead.