Truncate in a stored procedure or trigger?

Question

hello all,
is it possible to use 'truncate table' in trigger or stored procedure ?
I can do a delete, but when i use truncate table <mytable>, when i compile the trigger, i get an error,
the word 'TABLE' seems forbidden.
thanks for help

Answer 1

Hi Laurent,
I tryed to describe the work-around above.
Let me explain in details.
If you want to use 'TRUNCATE TABLE B' comand from a insert trigger on A, you can do the following:
1) create stored procedure which is autonomous
transaction:
create or replace procedure z1
is
pragma autonomous_transaction;
begin
execute immediate 'TRUNCATE TABLE B';
end;
You don't need put there explicit COMMIT -
it will be executed implicitly (autonomous
transactions require commit or rollback before
completon).
2) Create trigger on A for example:
create trigger trr
before insert on A
begin
z1;
end;
After issuing INSERT command for table A, table B
will be truncated.
Consider the following waterstones here:
1) In contrast with the using of DELETE, if you will
do rollback the changes after insertion in A - everything will rollbacked - except for B truncation. It's already
committed in another transaction. You are not able
to rollback the results of TRUNCATE.
2) If you do uncommitted changes in table B before
insertion in A - you will have
'ORA-00054: resource busy and acquire with NOWAIT specified'
exception because you can't truncate table where another
transaction makes changes.
Regards.