PL SQL Loop Table after insert and update - sql

Question

I'm trying loop through a table called broker after an insert to a different table called appointment and update a value on the broker table this what i have. When i try to create the trigger it comes up with an error saying "Trigger created with compilation errors"
CREATE OR REPLACE TRIGGER broker_level_trigger
AFTER INSERT ON appointment
DECLARE
counter integer := 1;
BEGIN
for o in (SELECT * FROM broker)
loop
SELECT COUNT(appointment.broker_id) INTO app_number FROM appointment INNER JOIN broker ON broker.broker_id = appointment.broker_id WHERE broker.broker_id = counter;
IF app_number > 15 THEN
UPDATE broker SET broker_level = 'gold' WHERE broker_id = counter;
counter := counter + 1;
end loop;
end;
/
The broker table has a field called broker_level and it changes based on the appointments, i want it to change if the broker_id field on appointments gets to more then 15

Answer 1

show err is a wonderful thing. (I created dummy tables you use).
SQL> CREATE OR REPLACE TRIGGER broker_level_trigger
2 AFTER INSERT ON appointment
3 DECLARE
4 counter integer := 1;
5 BEGIN
6 for o in (SELECT * FROM broker)
7 loop
8 SELECT COUNT(appointment.broker_id)
9 INTO app_number
10 FROM appointment INNER JOIN broker
11 ON broker.broker_id = appointment.broker_id
12 WHERE broker.broker_id = counter;
13
14 IF app_number > 15 THEN
15 UPDATE broker SET
16 broker_level = 'gold'
17 WHERE broker_id = counter;
18 counter := counter + 1;
19
20 end loop;
21 end;
22 /
Warning: Trigger created with compilation errors.
SQL> show err
Errors for TRIGGER BROKER_LEVEL_TRIGGER:
LINE/COL ERROR
-------- -----------------------------------------------------------------
18/7 PLS-00103: Encountered the symbol "LOOP" when expecting one of
the following:
if
If you look closer, you'll see that IF misses its END IF. Let's add it:
SQL> CREATE OR REPLACE TRIGGER broker_level_trigger
2 AFTER INSERT ON appointment
3 DECLARE
4 counter integer := 1;
5 BEGIN
6 for o in (SELECT * FROM broker)
7 loop
8 SELECT COUNT(appointment.broker_id)
9 INTO app_number
10 FROM appointment INNER JOIN broker
11 ON broker.broker_id = appointment.broker_id
12 WHERE broker.broker_id = counter;
13
14 IF app_number > 15 THEN
15 UPDATE broker SET
16 broker_level = 'gold'
17 WHERE broker_id = counter;
18 counter := counter + 1;
19 END IF; --> missing
20 end loop;
21 end;
22 /
Warning: Trigger created with compilation errors.
SQL> show err
Errors for TRIGGER BROKER_LEVEL_TRIGGER:
LINE/COL ERROR
-------- -----------------------------------------------------------------
6/5 PL/SQL: SQL Statement ignored
7/12 PLS-00201: identifier 'APP_NUMBER' must be declared
8/7 PL/SQL: ORA-00904: : invalid identifier
12/5 PL/SQL: Statement ignored
12/8 PLS-00201: identifier 'APP_NUMBER' must be declared
APP_NUMBER is missing now; you use it, but never declared it. Let's do it now:
SQL> CREATE OR REPLACE TRIGGER broker_level_trigger
2 AFTER INSERT ON appointment
3 DECLARE
4 counter integer := 1;
5 app_number number; --> missing
6 BEGIN
7 for o in (SELECT * FROM broker)
8 loop
9 SELECT COUNT(appointment.broker_id)
10 INTO app_number
11 FROM appointment INNER JOIN broker
12 ON broker.broker_id = appointment.broker_id
13 WHERE broker.broker_id = counter;
14
15 IF app_number > 15 THEN
16 UPDATE broker SET
17 broker_level = 'gold'
18 WHERE broker_id = counter;
19 counter := counter + 1;
20 END IF; --> missing
21 end loop;
22 end;
23 /
Trigger created.
SQL>
That would be it.
If you don't use SQL*Plus but some other tool, you can always query user_errors:
Warning: Trigger created with compilation errors.
SQL> select line, position, text from user_errors where name = 'BROKER_LEVEL_TRIGGER' order by sequence;
LINE POSITION TEXT
----- --------- ------------------------------------------------------------
8 12 PLS-00201: identifier 'APP_NUMBER' must be declared
9 7 PL/SQL: ORA-00904: : invalid identifier
7 5 PL/SQL: SQL Statement ignored
13 8 PLS-00201: identifier 'APP_NUMBER' must be declared
13 5 PL/SQL: Statement ignored
SQL>