CURSOR c_test IS
SELECT column_name FROM SYS.ALL_TAB_COLUMNS WHERE TABLE_NAME=TG_RELNAME AND OWNER=USER;
.
.
v_sql:='select decode(:new.'||v_column_name||','||':old.'||v_column_name||',0,1) from dual';
EXECUTE IMMEDIATE v_sql INTO v_num ;
if v_num=1 then
insert into log_file (num,string)values (a,v_column_name);
.
.