Basic help needed creating a trigger

Question

I'm completely new to SQL programming altogether, and I'm trying to set up a trigger that will make some checks before adding a new row to a given table. I am trying to do this because I need to enforce a CONSTRAINT that checks whether the dates entered for 'deadline' and 'startDate' are greater than sysdate and less than (sysdate + 365), and I found out that you cannot reference sysdate from a CONSTRAINT. Therefore I am now attempting to do this using a trigger, but I don't really know how to do this. Here is the sql code used to create the table:
-- PLACEMENT TABLE
DROP TABLE placement;
CREATE TABLE placement
contactId Int,
placementId Int,
position VARCHAR(60),
description CLOB,
lengMonths Int,
salary Number(7,2),
deadline DATE,
startDate DATE,
addrLine1 VARCHAR(120),
postCd VARCHAR(10)
And here is my attempt at creating the trigger that will only allow the deadline and startDate to be entered if they satisfy the following check: (sysdate < deadline/startDate <= sysdate+365)
CREATE OR REPLACE TRIGGER trg_deadline_low BEFORE INSERT OR UPDATE OF deadline ON placement
BEGIN
IF :deadline <= SYSDATE THEN
ROLLBACK;
END IF;
END;
CREATE OR REPLACE TRIGGER trg_deadline_high BEFORE INSERT OR UPDATE OF deadline ON placement
BEGIN
IF :deadline > SYSDATE + 365 THEN
ROLLBACK;
END IF;
END;
If possible, I would like for these triggers to display an error rather than just using ROLLBACK, but I'm not sure how! At the moment, these triggers do not work at all; I get an error message "Warning: Trigger created with compilation errors." when I attempt to create the triggers in the first place.
Can anyone tell me why I am seeing this error when trying to implement the triggers? And if anyone could also improve on my amateur attempt at coding a trigger, then that would be great! Thanks for any help!

Answer 1

Oops!
Nicolas, Thank you for correcting my mistake.
SQL> edit
Wrote file afiedt.buf
1 CREATE TABLE placement
2 (
3 contactId Int,
4 placementId Int,
5 position VARCHAR(60),
6 description CLOB,
7 lengMonths Int,
8 salary Number(7,2),
9 deadline DATE check (deadline between sysdate and sysdate+365),
10 startDate DATE,
11 addrLine1 VARCHAR(120),
12 postCd VARCHAR(10)
13* )
SQL> /
deadline DATE check (deadline between sysdate and sysdate+365),
ERROR at line 9:
ORA-02436: date or system variable wrongly specified in CHECK constraint
SQL> edit
Wrote file afiedt.buf
1 CREATE TABLE placement
2 (
3 contactId Int,
4 placementId Int,
5 position VARCHAR(60),
6 description CLOB,
7 lengMonths Int,
8 salary Number(7,2),
9 deadline DATE check (deadline between to_date('2007-03-21','yyyy-mm-dd') and to_date('2008-03-21','yyyy-mm-dd')
10 startDate DATE,
11 addrLine1 VARCHAR(120),
12 postCd VARCHAR(10)
13* )
SQL> /
Table created.
On the contrary, I think that OP want an error instead of rollback : "I would like for these triggers to display an error rather than just using ROLLBACK"Ah, I had misread additionally. Sorry.