How do I check that a varchar2 variable in PL/SQL is like 10 characters in a trigger? And does it automatically proceed with the insert it its good?
--trigger that checks that number of characters are 10, doesnt work
create or replace trigger checkthings
before insert or update
on tblTenChars
declare
noGood exception;
begin
if :new.justTenVars(size) <> 10 then --this is not the way?
raise noGood;
end if;
exception
when noGood then
raise_application_error(-20008, 'Wrong not 10 characters');
end;
I would use a check constraint, not a trigger:
alter table tblTenChars add constraint checkthings
check (length(justTenVars) = 10);
A check constraint is simpler and more efficient.
But for completeness, the trigger code would be:
create or replace trigger checkthings
before insert or update
on tblTenChars
for each row
begin
if length(:new.justTenVars) <> 10 then
raise_application_error(-20008, 'Wrong not 10 characters');
end if;
end;
If the exception is raised, the insert or update is aborted; otherwise it takes place.