CREATETABLE tbl_logoff

(

  who VARCHAR2(30),

  whenDATE

);

CREATEORREPLACETRIGGER trg_logoff_db

  BEFORE LOGOFF ONDATABASE

BEGIN

  INSERTINTO tbl_logoff

  VALUES

    (SYS_CONTEXT('userenv',

                 'session_user'),

     SYSDATE);

END;

/

CREATETABLE tbl_logon

(

  who VARCHAR2(30),

  whenDATE

);

CREATEORREPLACETRIGGER trg_logon_db

  AFTER LOGON ONDATABASE

BEGIN

  INSERTINTO tbl_logon

    (who,

     WHEN)

  VALUES

    (USER,

     SYSDATE);

END;

/