Max Wanadoo
max.wanadoo at gmail.com
Wed Mar 5 14:02:44 CST 2008
Thanks Jim, Most useful. Regards Max -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Jim Lawrence Sent: Wednesday, March 05, 2008 4:51 PM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Error 3048 Cannot open any more databases Hi Max: Most ADO recordsets are not tied to the database where the data is retrieved. That is not a disconnected recordset just one that is not dynamically linked. To dynamically connect a ADO recordset to the database would have use something like: ' By using the operand adOpenDynamic the recordset ' below remains linked to the dataset this process has retrieved ' and if any data changes take place during the use this recordset ' those changes are dynamically reflected in recordset. rsMyRecordset.Open objCmd, , adOpenDynamic, adLockOptimistic ' Below is the most likely code to retrieve data for something like a ' combo box object which does not require a dynamic link. The ' connection to the database is terminated immediately after ' the data has been retrieved. rsMyRecordset.Open objCmd, , adOpenStatic, adLockOptimistic HTH Jim -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of jwcolby Sent: Wednesday, March 05, 2008 5:33 AM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Error 3048 Cannot open any more databases Max, To be honest I am not the one to be answering these questions since none of my clients have required this feature, and in fact several of my clients are still running access 2000 or a mix with 2000 included which disallows general use of this feature - Access 2000 can't bind a form to an EDITABLE ADO recordset. It would be interesting to discover whether using ADO would speed up a database application as the number of users rise. If you think about it, Access has to go through all of the connections discovering whether they might need to update data. At one client, I work "offline" much of the time, mapping local directories to a drive letter for testing, then mapping network shares to that same drive letter for live access to data. When I am offline I get immediate opening of very complex forms. When working live it can require seconds to open the same form. If there are a hundred active connections per user (combos, lists, forms, subforms etc), times 40 users that is a lot of connections for Jet to wade through. Imagine just making all of the combos bound to disconnected ADO recordsets. That would drop the active connections at least by half, probably more like 80%. I have a billing database here at my office that I will spend some time this morning playing with this stuff and see what I see. However I believe there are others on the list who already do this and could help us figure out how it is done. 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 Max Wanadoo Sent: Wednesday, March 05, 2008 8:00 AM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Error 3048 Cannot open any more databases Well, I never knew that. Learn something every day. Do you have to tell ADO to disconnect or does it do it automatically. If auto, then do you assume it is closed in all cases and re-open it to do something with it or do you test it (somehow) to see if it is disconnected? Thanks Max -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of jwcolby Sent: Wednesday, March 05, 2008 12:15 PM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Error 3048 Cannot open any more databases Max, When you run a normal query in a combo or list or form etc. that is handled by JET as a normal DAO recordset. There is a fixed number of such recordsets available to your application, the number being up somewhere around 2000, which sounds like a lot but... At any rate, in later versions of Access, access allows you to manually create ADO recordsets and bind things like combos, lists and forms to those recordsets. ADO can disconnect once it has pulled the data, whereas DAO (to my knowledge) does not have that capability. IOW ADO can actually close its connection to the database after pulling its data. For combos this is not an issue, but for forms it creates issues where you have to make sure that the data that you pulled from has not changed if you are going to write your own changes back. 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 Max Wanadoo Sent: Wednesday, March 05, 2008 4:33 AM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Error 3048 Cannot open any more databases John, What do you mean by "disconnected" recordsets? Max -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of jwcolby Sent: Wednesday, March 05, 2008 3:20 AM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Error 3048 Cannot open any more databases Yup! If you are using Access XP or above, look at binding all combos and lists to disconnected ADO recordsets. That will help immensely all by itself. After that you will probably need to dive into the dark arts of ADO disconnected recordsets for the form as well. As Charlotte said, WANS are considered a no-no for bound forms in Access. 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 Charlotte Foust Sent: Tuesday, March 04, 2008 8:08 PM To: Access Developers discussion and problem solving Subject: Re: [AccessD] Error 3048 Cannot open any more databases Darryl, This is a highly misleading message, because it really means you have too many connections open. If you are doing things like populating combo boxes with select statements, each one of them is opening a connection. As I recall, lookups in your tables could do that as well. Access was NOT meant for WAN use, and to make it even marginally reliable in that context, you have to rewrite the UI to eliminate any unnecessary connections to the back end and use a JIT approach to populating lists, forms, subforms, etc. There have been previous discussions on this in the list, so you might take a stroll through the archives and see what you find. Charlotte Foust -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Darryl Collins Sent: Tuesday, March 04, 2008 4:23 PM To: Access Developers discussion and problem solving Subject: [AccessD] Error 3048 Cannot open any more databases Hey folks, Sorry to bug you with this, Having a lot of, ummm, 'fun' with this database I am building. Stand alone, it works great, with 5 or so users it works great, over a WAN with multi users it gets very wobbly and corrupts easily. Decided that it has to be split into FE and BE, which I have done manually and linked up the tables. When the DB opens it populates a listbox with choices for the user as before fine. However when the users selects an option which opens the data-entry form (and associated subforms) I get this lovely error "Error 3048 Cannot open any more databases" on this line sSQL = "SELECT * FROM tbl_FYP_APLID WHERE (((FYPID)=" & lFYPID & ") AND ((tbl_FYP_APLID.APLID)=" & lAPLID & "));" [Forms]![frm_FYP_APLID].RecordSource = sSQL Now I know clearly that I must have too "many databases open", but exactly what the hell does that mean? how did it happen and how can I either 1: increase the amount of DB's I can have open, or close down some of the offending databases? The only clue I have found online is if you don't SET your delcared CurrentDB to NOTHING when you are done with it, But the code in this workbook doesn't work like that at all and the modules that do use SET current DB, does set them to nothing when finished. Most confusing. Can anyone shed some light on this. Sorry about all the questions - working under lot of pressure and learning on the fly. Educational for sure, but I am getting through more and more scotch in the evening!! :) Darryl. -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com