About DDL triggers

Question

create or replace trigger no_create
before create on database
begin
raise_application_error(-20500, 'This is a before trigger...:' || ora_dict_obj_name );
end;
create table deletemenow(one varchar2(40));object not created...great thats what i wanted
create or replace trigger no_create
after create on database
begin
raise_application_error(-20500, 'This is a after trigger...:' || ora_dict_obj_name );
end;
create table deletemenow(one varchar2(40));object not created, but doesn't this trigger fire after the object is created and so shouldn't the table be created anyway since the trigger fires too late! So how does this trigger actually work?
If i run this....
create or replace trigger no_create
before create on database
begin
raise_application_error(-20500, 'This is a before trigger...:' || ora_dict_obj_name );
end;....and then i try to run
create or replace trigger another_no_create
before create on database
begin
raise_application_error(-20500, 'This is a before trigger...:' || ora_dict_obj_name );
end;
ERROR at line 2:
ORA-00604: error occurred at recursive SQL level 1
ORA-20500: This is a before trigger...:ANOTHER_NO_CREATE
ORA-06512: at line 2...make sense. But if i execute this...
create or replace trigger no_create
before create on database
begin
raise_application_error(-20500, 'This is a before trigger...:' || ora_dict_obj_name );
end;...no problem, why is this (pretty smart of Oracle actually)?
Cheers
Gus

Answer 1

If the trigger throws up an exception which is successfully handled by the trigger the DML that caused the trigger will complete successfully. If not the DML within the trigger and the DML that caused the trigger will fail :)
I don't need a lesson in triggers from you Justin, all i was raising was the fact that DDL statements have an implied commit and so to write an AFTER DDL trigger seemed a bit like writing an AFTER SHUTDOWN trigger. I know thats not how its handled but you seemed to have missed the question...why, is there a reason
When the second trigger succeeds, thats becaause you
are replacing the old trigger (CREATE OR REPLACE).
It would be pretty silly if Oracle didn't allow you
to modify a particular database object.I don't see it that way (CREATE OR REPLACE) is not a MODIFY as you seem to think, its a CREATE OR REPLACE.
Gus