You can program your own ON-LOCK trigger on that block that does the equivalent of what forms does. Lets say you have a block on DEPT. You could code an ON-LOCK trigger on that block like:


declare
resource_busy exception;
pragma exception_init( resource_busy, -54 );
l_deptno number;
begin
for i in 1 .. 3
loop
begin
select deptno into l_deptno
from dept
where rowid = :dept.rowid
and deptno = :dept.deptno
and dname = :dept.dname
and loc = :dept.loc
FOR UPDATE NOWAIT;

RETURN;
exception
when resource_busy then
null;
when no_data_found then
message( 'Sorry, row was changed by some other
session, please requery it' );
end;
end loop;

message( 'Bummer, someone else has this locked!!!!' );
raise form_trigger_failure;
end;


The logic is basically the same as what forms does for you automatically. It'll try to query the row up with a FOR UPDATE NOWAIT by rowid using all of the values in the block. If we get resource_busy, someone has it locked -- try again. If we get no data found -- the rows values have changed since we queried it -- you lose. Otherwise we return and the record is locked by our session. After trying three times -- we'll give up and return our own message about the row being locked.