Re: Cursors

Hi, Append "FOR UPDATE" onto the end of the $select_statement string. -Bill } } Art S. Kagel wrote: } } > Nils' suggestion is excellent, however, it does not protect your users } > from overwriting data changed by others while he/she is editing the } > current record, as Nils points out. Immediately before updating the } > record you should FETCH the row that you are about to update with a } > CURSOR...FOR UPDATE so that the row is locked and compare the values } > returned for all columns, or for an indicative column like a timestamp } > or update count, to the original values that you FETCHED. Then only if } > the values have not changed UPDATE ... WHERE CURRENT OF <cursorname of } > cursor for update>. This will give you the safety of locking rows but } > permits greater concurrency since the lock in only momentary. } } Perhaps you can help me with with doing this in ESQL/C. } } I'd like to do something like: } } $ prepare select_id from $select_statement; } } $ describe select_id into in_vals; } } $ declare sel_cursor cursor for select_id for update; } } $ prepare update_id from "update set column1 = ? where current of } sel_cusor; } } $ execute update_id using in_vals; } } } The problem is that $declare will not let me use a prepared statement id } with the } "for update" keywords. Thus I cannot dynamically set the "select cursor for } update". } } Any ideas on how to do this? } } Phil } } -- } -------------------------------------------------------------------------- } Philip Walden } Hewlett Packard } Supply Chain Information Systems } 1501 Page Mill Road, M/S 5L-A } Palo Alto, CA 94304 } (415) 857-3899 FAX (415) 857-8234 } http://www.pgis.hp.com/~pwalden } mailto:phil_walden@hp.com } -------------------------------------------------------------------------- } } } } -- Bill Ennis Voice: 312-474-7516 SSA Fax: 312-474-7460 500 W. Madison email: ennis@ssax.com ennis@accesschicago.net