Martin Reid
mwp.reid at qub.ac.uk
Fri Dec 22 11:44:29 CST 2006
Thanks folks Actually I am thinking of adding this dicussion into the chapter. I find it interesting as well. I dont know enough about classes yet to take this on and I dont have time at the moment as this one needs to be done this evening. If anyone objects to me adding part of the conversation into the chpater drop me a line of list. Martin Martin WP Reid Training and Assessment Unit Riddle Hall Belfast tel: 02890 974477 ________________________________ From: accessd-bounces at databaseadvisors.com on behalf of Charlotte Foust Sent: Fri 22/12/2006 17:28 To: Access Developers discussion and problem solving Subject: Re: [AccessD] Unbound Again I assume you mean record locking, not control locking, Martin. I've done it with ADO but I can't remember ever bothering with DAO. When ADO first came in with Access 2000, you couldn't bind a form to an ADO recordset and make it editable, so you had to use unbound forms and I learned. If you're dealing with DAO, one alternative is a bound unbound form, where the form has a bound recordset, but the controls are unbound. That allows you to lock the record and still use unbound controls. It takes more work though. Charlotte Foust -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Martin Reid Sent: Friday, December 22, 2006 9:08 AM To: Access Developers discussion and problem solving Subject: Re: [AccessD] Unbound Again I am thinking that locking is the key to working unbound. All the other stuff is nice and easy really. Add, Edit, Delete etc is very much standard stuff. Its the locking that will catch many people out. Maybe I should write up a bit on that for this section. Martin Martin WP Reid Training and Assessment Unit Riddle Hall Belfast tel: 02890 974477 ________________________________ From: accessd-bounces at databaseadvisors.com on behalf of Jim Lawrence Sent: Fri 22/12/2006 16:48 To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Unbound Again Hi Martin: John is right about the locking issues. Until recently when trying to lock a specific record in Access the DAO database would lock a group of records. The way to handle that is to: All tables should have a timestamp, locked and user code field. When a record's contents are pulled into a (disconnected) recordset, the records' timestamp and user code field is immediately updated and the lock field is set. After the editing process is completed the table record is updated and the lock field is cleared. This is very similar to the way both MS SQL and Oracle manage their tables. HTH Jim -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of JWColby Sent: Friday, December 22, 2006 6:45 AM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Unbound Again Martin, One problem with unbound is the whole locking issue, which the bound method handles for you. Unless you place a lock on the record you are editing, then how do you know that the underlying record wasn't updated by another user while this user was eating lunch? Thus for simple unbound, probably only updating fields changed is the safest. If your form is going to lock the record being edited, then you can safely update the entire record. Or you could refetch the original, compare the field values of the original to the "old values" of the unbound form, and warn the user if there were changes to the original. Many different answers to that seemingly simple question. John W. Colby Colby Consulting www.ColbyConsulting.com -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Martin Reid Sent: Friday, December 22, 2006 8:10 AM To: Access Developers discussion and problem solving Subject: [AccessD] Unbound Again Back to the unbound edit So the idea I am using is to 1. Click The Edit Button 2. Unlock fields 2. Change edit caption to save So the suer changes one field. Do you just simply update the whole record ot do you test each field and only chane the one edited? Or is there any issue with either? Martin Martin WP Reid Training and Assessment Unit Riddle Hall Belfast tel: 02890 974477 -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com <http://www.databaseadvisors.com/> <http://www.databaseadvisors.com/> -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com <http://www.databaseadvisors.com/> <http://www.databaseadvisors.com/> -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com <http://www.databaseadvisors.com/>