Triger issue

Question

Hai all,
I have a "BEFORE INSERT OR DELETE ON" row level trigger on one table t1, in that trigger
I am doing update statement on tha same table and that work fine. My requierment is to make
an insert on that table, but that is not possible with this dml triger trigger
my criteria is like this
if inserting a new value with id 1 i hav to update old values with id 1 and if old value not exists with that id
i have to insert a new row in that table
any other way to do this, please help in this regard
DB version - ORACLE 10 G Release 2
Regards
Hari K P

Answer 1

Hari1984 wrote:
in that trigger I am doing update statement on tha same table and that work fine. No it doesn't. It will work only if you insert or delete just one row. Inserting or deleting multiple rows will result in:
SQL> create table tbl1(n number);
Table created.
SQL> create or replace
  2    trigger tbl1_bidr
  3      before insert
  4          or delete
  5      on tbl1
  6      for each row
  7      begin
  8          update tbl1
  9             set n = 10
10             where n = 1;
11  end;
12  /
Trigger created.
SQL> insert
  2    into tbl1
  3    values(1)
  4  /
1 row created.
SQL> insert
  2    into tbl1
  3    select  empno
  4      from  emp
  5  /
  into tbl1
ERROR at line 2:
ORA-04091: table SCOTT.TBL1 is mutating, trigger/function may not see it
ORA-06512: at "SCOTT.TBL1_BIDR", line 2
ORA-04088: error during execution of trigger 'SCOTT.TBL1_BIDR'
SQL> DML against triggering table inside a trigger indicates design issues.
SY.