Question

I have a trigger which is supposed to test whether an individual punching a time clock has punched their card within the last 5 minutes. If they have not their info should be left to go on to the table clk_data, otherwise a record should be made in the log table utl_logbook and the insert to clk_data should be aborted.

When I run a good punch the insert works as advertised. When it is a bad punch (within 5 minutes of the last punch) I get the following error:

SQL Error: ORA-20101: Too Soon
ORA-06512: at "TRUTRACK.INSERT_CLK_DATA", line 14
ORA-04088: error during execution of trigger 'TRUTRACK.INSERT_CLK_DATA'

The transaction is stopped but I get no recording of it in utl_logbook.

The trigger code:
create or replace
TRIGGER "INSERT_CLK_DATA" 
BEFORE INSERT ON clk_data 
FOR EACH row 

BEGIN
  DECLARE qty INTEGER := 0;
  BEGIN
    SELECT COUNT(*)
    INTO qty
    FROM clk_data
    WHERE clk_time BETWEEN (:new.clk_time - 5/(24*60)) AND (:new.clk_time + 5/(24*60))
    AND :new.payroll = clk_data.payroll;

    IF qty > 0 THEN

      INSERT INTO utl_logbook (time, source, message) VALUES (sysdate, 'INSERT_CLK_DATA', 'Clock punch within restricted window. Payroll ID:' || :new.payroll || ' Time: ' || :new.clk_time || ' Type: ' || :new.type);

      RAISE_APPLICATION_ERROR(-20101, 'Too Soon');

    END IF;

  END;
END;

Answer 1

This is can be one of those rare cases when you can employ pragma autonomous_transaction. It will allow you commit without affecting your main transaction. Use it with caution. Find out more about autonomous transactions and autonomous_transaction pragma

Here is an example:

   -- our error logging table 

   create table tb_log(
      msg varchar2(123)
    )
    /

   -- our working table
   create table tb_table(
     col11 number
    )
    /

-- procedure that is going to log errors


NK@XE> create or replace procedure log_error(p_msg in varchar2)
  2    is
  3      pragma autonomous_transaction;
  4    begin
  5      insert into tb_log(msg)
  6        values(p_msg);
  7      commit;
  8    end;
NK@XE> /

Procedure created.

NK@XE> create or replace trigger tr_tb_table
  2    before insert on tb_table
  3    for each row
  4    begin
  5      if mod(:new.col1, 2) != 0
  6      then
  7         log_error('Error!');
  8         raise_application_error(-20000, 'Error has ocurred!');
  9      end if;
 10    end;
 11  /

Trigger created.

NK@XE> select * from tb_log;

no rows selected

NK@XE> select * from tb_table;

no rows selected

NK@XE> insert into tb_table(col1) values(1);

insert into tb_table(col1) values(1)
            *
ERROR at line 1:
ORA-20000: Error has ocurred!
ORA-06512: at "NK.TR_TB_TABLE", line 5
ORA-04088: error during execution of trigger 'NK.TR_TB_TABLE'


NK@XE> select * from tb_log;

MSG
--------------------------------------------------------------------------------
Error!