Oracle trigger invalid - database

Question

I'm new to SQL and I'm trying to create a trigger that would insert into an audit table.
create or replace trigger late_ship_insert
after insert on suborder
for each row
declare
employee int;
begin
select emp_id
into employee
from handles
where order_no = :new.order_no;
if :new.actual_ship_date > :new.req_ship_date then
insert into ship_audit
values (employee, :new.order_no, :new.suborder_no, :new.req_ship_date, :new.actual_ship_date);
end;
Error:
Warning: execution completed with warning
trigger late_ship_insert Compiled.
But once I try an insert statement it tell me the trigger is not working it to drop it.
Error starting at line 1 in command:
insert into suborder
values ( 8, 3, '10-jun-2012', '12-jul-2012', 'CVS', 3)
Error at Command Line:1 Column:12
Error report:
SQL Error: ORA-04098: trigger 'COMPANY.LATE_SHIP_INSERT' is invalid and failed re-validation
04098. 00000 - "trigger '%s.%s' is invalid and failed re-validation"
*Cause: A trigger was attempted to be retrieved for execution and was
found to be invalid. This also means that compilation/authorization
failed for the trigger.
*Action: Options are to resolve the compilation/authorization errors,
disable the trigger, or drop the trigger.
Any idea what is causing this, any help would be greatly appreciated. Thanks!

Answer 1

The error that becomes apparent when you format your code is that your IF statement is missing the END IF
create or replace trigger late_ship_insert
after insert on suborder
for each row
declare
employee int;
begin
select emp_id
into employee
from handles
where order_no = :new.order_no;
if :new.actual_ship_date > :new.req_ship_date then
insert into ship_audit
values (employee, :new.order_no, :new.suborder_no, :new.req_ship_date, :new.actual_ship_date);
end if;
end;
As a general matter, you should always list the columns of the destination table in your INSERT statement rather than relying on the fact that your INSERT statement specifies a value for every column and specifies them in the proper order. That will make your code much more robust since it won't become invalid when someone adds additional columns to the table for example. That would look something like this (I'm guessing at the names of the columns in the ship_audit table)
create or replace trigger late_ship_insert
after insert on suborder
for each row
declare
employee int;
begin
select emp_id
into employee
from handles
where order_no = :new.order_no;
if :new.actual_ship_date > :new.req_ship_date then
insert into ship_audit( emp_id, order_no, suborder_no, req_ship_date, actual_ship_date )
values (employee, :new.order_no, :new.suborder_no, :new.req_ship_date, :new.actual_ship_date);
end if;
end;