pl sql error when working with trigger - oracle

Question

I get an error when working with the following trigger:
create or replace trigger t1
after insert or update
on student_tbl
declare
pragma autonomous_transaction;
begin
if inserting then
insert into stud_fees_details(stud_id,fees_balance,total_fees)
select stud_id,course_fees,course_fees from student_tbl s,courses_tbl c where s.stud_standard_id=c.course_id;
elsif updating('stud_standard_id') then
insert into stud_fees_details(stud_id,fees_balance,total_fees)
select stud_id,course_fees,course_fees from student_tbl s,courses_tbl c where s.stud_standard_id=c.course_id;
end if;
end;
error is
ORA-06519: active autonomous transaction detected and rolled back
ORA-06512: at "SYSTEM.T1", line 15
ORA-04088: error during execution of trigger 'SYSTEM.T1'

Answer 1

Database Error Messages
ORA-06519: active autonomous transaction detected and rolled back
Cause: Before returning from an autonomous PL/SQL block, all autonomous transactions started within the block must be completed (either committed or rolled back). If not, the active autonomous transaction is implicitly rolled back and this error is raised.
Action: Ensure that before returning from an autonomous PL/SQL block, any active autonomous transactions are explicitly committed or rolled back.
Example from Database PL/SQL Language Reference
-- Autonomous trigger on emp table:
CREATE OR REPLACE TRIGGER log_sal
BEFORE UPDATE OF salary ON emp FOR EACH ROW
DECLARE
PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
INSERT INTO log (
log_id,
up_date,
new_sal,
old_sal
)
VALUES (
:old.employee_id,
SYSDATE,
:new.salary,
:old.salary
);
COMMIT;
END;
/
But #a_horse_with_no_name already stated that an autonomous transaction maybe is is not appropriate here.
After removing the autonomous transaction pragma you maybe will run into the problem that #GordonLinoff adresses with his post.

Answer 2

If a trigger doesn't use :new or :old, then it is suspicious. Your trigger is using the same table being modified in queries.
You probably intend:
create or replace trigger t1 after insert or update on student_tbl
declare
pragma autonomous_transaction;
begin
if inserting then
insert into stud_fees_details(stud_id, fees_balance, total_fees)
select stud_id, course_fees, course_fees
from courses_tbl c
where c.course_id = :new.stud_standard_id;
elsif updating('stud_standard_id') then
insert into stud_fees_details(stud_id, fees_balance, total_fees)
select stud_id, course_fees, course_fees
from courses_tbl c
where c.course_id = :new.stud_standard_id;
end if;
commit;
end;
Notes:
The select statements should have table aliases, to distinguish the columns that come from :new and from courses_tbl.
The two clauses to the if look the same to me, so I don't understand the logic.
The join conditions between something called course_id and somethign called stud_standard_id looks suspicious. I would advise you to name foreign keys after the primary key they refer to.