Multi-user updates using the OWS without Locking Tables

SELECT and an UPDATE initiated from a Web Browser occur at different
times on the Web because HTTP doesn't maintain state.  A workaround is
to let the PL/SQL display the data for updating also store the data
values in hidden HTML fields. For Example: 

   for x in (select rowid, a.* from emp a) loop
      htp.FormHidden('the_rowid', x.rowid);
      htp.Print('Enter new Employee Name:');
      htp.FormHidden('old_ename',x.ename);
      htp.FormText('new_ename', x.ename);
   end loop;

The values in the form with can now be compared to the current table 
values before allowing the update occur. For Example: 

   UPDATE emp SET ename = new_ename
   WHERE rowid = the_rowid
     AND ename = old_ename;

   if (SQL%ROWCOUNT = 0) then
      htp.print('Row has Changed, please re-query before updating.');
   else
      htp.print('Row updated.');
   end if;

If the Update occurs it is done to the data because it matched data from
the select.  If the current data doesn't match, the user is told to 
re-query the data.  This will work in a low transactional system, but 
may be annoying to users in a high transaction systems.