Trigger used in forms :

Type : User defined.
          Oracle provided.


go_field('adm_rec_amount');----same block so no need prefix.

--- KEY-NEXT-ITME :

This trigger can use procedure(user defined) like prc_search procedure  ;
Example :
PROCEDURE prc_search IS

  V_DW_NEW VARCHAR2(4000);

BEGIN
  V_DW_NEW :=GET_BLOCK_PROPERTY('EMV_COMPLAIN',DEFAULT_WHERE);
  V_DW_NEW := 'company_no = :global.g_company_no';

IF :ctrl_blk.complain_src IS NOT NULL THEN
V_DW_NEW := V_DW_NEW||' AND upper(COMPLAIN_NAME) LIKE ''%''||upper(:CTRL_BLK.COMPLAIN_SRC)|| ''%'' ';
END IF;

GO_BLOCK('EMV_COMPLAIN');
CLEAR_BLOCK(NO_VALIDATE);
  SET_BLOCK_PROPERTY('EMV_COMPLAIN',ONETIME_WHERE,V_DW_NEW );
  :SYSTEM.MESSAGE_LEVEL:=5;
EXECUTE_QUERY;         
:SYSTEM.MESSAGE_LEVEL:=0;

EXCEPTION
WHEN OTHERS THEN
MSGBOX(SQLCODE||' '||SQLERRM);

END;

------WHEN-VALIDATE-ITEM (( Trigger fires when item value is changed).)
example 1:
begin
if :ename is null then
message (‘Employee name cannot be blank’);
message(‘ ‘);
raise form_trigger_failure;
end if;
end;

example 2:

BEGIN

   IF :sal < 3000

   THEN

      MESSAGE (‘Employee sal must NOT be less than 3000’);

MESSAGE(‘ ‘);

raise form_trigger_failure;

end if;

end;

example 3:

--Here use hr schema table employees filed(EMPLOYEE_ID)

--

begin

message('Here use global variable,record status');

message(:system.record_status);

select :EMPLOYEES.EMPLOYEE_ID into :global.v1

from dual;

if :global.v1 =1

then message(:global.v1);

else 

:global.v1:=2;

message(:global.v1);

end if;

end;

screen short :

-------When-new-item-instance;

Properties : Item level trigger .
Effect in form :
Image after  use this trigger :

Image before  use this trigger :

Block Level Trigger :

When-new-record-instance

Example : Auto number generate:

:PM_RXCHD.MED_SL := :system.trigger_record;