Trigger compilation error reasons - sql

Question

Hi guys I have two triggers I am meant to be be creating but I am getting compilation errors on both
this first is supposed to record evaluations of 0 to an audit table and the second is supposed to prevent the deletion of entries in which the date is less than todays date.
SQL> CREATE TABLE EVALUATION_AUDIT
2 (C_NAME VARCHAR (15), CO_ID NUMBER(7), E_DATE DATE,
3 V_ID NUMBER (7), C_EVALUATION NUMBER(1));
Table created.
SQL> CREATE OR REPLACE TRIGGER ZERO_EVAL
2 BEFORE INSERT OR UPDATE OF C_EVALUATION ON CUSTOMER_EVENT
3 FOR EACH ROW
4 WHEN (NEW.C_EVALUATION = 0)
5 BEGIN
6 SELECT C_NAME, CO_ID, E_DATE, V_ID, C_EVALUATION
7 FROM CUSTOMER_EVENT CE, CUSTOMER C, EVENT E
8 WHERE CE.C_ID = C.C_ID
9 AND CE.EVENT_ID = E.EVENT_ID
10 AND C_EVALUATION = NEW.C_EVALUATION;
11 INSERT INTO EVALUATION AUDIT
12 VALUES (:NEW.C_NAME, :NEW.CO_ID, :NEW.E_DATE, :NEW.V_ID, :NEW.C_EVALUATION);
13 END;
14 /
Warning: Trigger created with compilation errors.
SQL> CREATE OR REPLACE TRIGGER PASTEVENTS
2 BEFORE DELETE
3 ON EVENT
4 FOR EACH ROW
5 BEGIN
6 IF :OLD.E_DATE =< SYSDATE
7 THEN RAISE_APPLICATION_ERROR (-20002, 'CAN NOT DELETE PAST EVENT RECORDS');
8
9 END IF;
10 END;
11 /
Warning: Trigger created with compilation errors.

Answer 1

As Justin said, when you get created with compilation errors for any stored PL/SQL, type show errors, or you can query the user_errors table to see all outstanding errors on your objects.
From a quick scan, the first trigger is missing a colon when you reference NEW.C_EVALUATION in the select:
AND C_EVALUATION = :NEW.C_EVALUATION;
You need to select into something, though I'm not sure if it's necessary here as you have the values from the :NEW psuedorecord; not sure why you're selecting at all?
And the second has an incorrect operator, =< instead of <=:
IF :OLD.E_DATE <= SYSDATE
It's generally a good idea to prefix column names with the table alias to avoid ambiguity, e.g. SELECT C.C_NAME, ... if that column comes from the CUSTOMER table, etc. You could have another error in there is you have the same column on multiple tables. And it's good practise to list the column names in your INSERT too, i.e. INSERT INTO EVALUATION_AUDIT (C_NAME, ...) VALUES (...). With the missing underscore that #Dba spotted!

Answer 2

In your first trigger code you don't need to SELECT from the tables as you are just inserting the values from the table CUSTOMET_EVENT to EVALUATION_AUDIT. Also you have missed and underscore _ in table_name in EVALUATION_AUDIT in line 11.
CREATE OR REPLACE TRIGGER zero_eval
BEFORE INSERT OR UPDATE OF c_evaluation ON customer_event
FOR EACH ROW
WHEN (NEW.c_evaluation = 0)
BEGIN
INSERT INTO evaluation_audit(c_name, co_id, e_date, v_id, c_evaluation)
VALUES (:NEW.c_name, :NEW.co_id, :NEW.e_date, :NEW.v_id, :NEW.c_evaluation);
END;
/
In Your second code, it should be <= instead of =<
CREATE OR REPLACE TRIGGER pastevents
BEFORE DELETE
ON event
FOR EACH ROW
BEGIN
IF :OLD.e_date <= SYSDATE THEN
raise_application_error (-20002, 'CAN NOT DELETE PAST EVENT RECORDS');
END IF;
END;
/