run program thru network

[enigmagirl122]

hi:wave:

i need your advise i created a program from vb6 and ms acces as my dbase. they want to install my program to our server and create a shortcut for each workstation.i feel that this is not a good idea and it will cause my program to run slow and worst errors.

is it possible to place my database in the server and install the program for each computer. it means i have to redirect my program to get the database from the server. is that possible? and can you give me an example.

thanks!

[Aforsythe]

Provided that you map a drive from each client to the location of the database, then sure. There is no remote database connectivity support in VB, but I have heard several people mention you can still do it.

Also, I don't know much about Access, but are there problems allowing multiple connections to a single database file using it?

[enigmagirl122]

I can connect now but i get run time error could not use "; file already in use. this error occur when 3 using the program, 2 of them is viewing and 1 of them is editing the record.


Thanks!

[dilettante]

Jet MDBs fully support multiple users. By default you get page-level locks which can lead to performance problems but row-level locking can also be requested.

"File already in use" errors must be something else. Perhaps your client is opening the MDB for exclusive access or failing to handle lock timeouts properly?


I'm not sure why anyone would think remote database access isn't supported by VB6. Keep in mind though that Jet is an embedded database technology though. Even putting the MDB file itself on a file server is not "remote" access. To use Jet for remote access you have to add a middleware layer, the standard one for years being Remote Data Service.

I doubt you want to go that way though, it's a deprecated techonlogy (though supplied even in Windows 7's Data Access Components) and an advanced topic.


Multi-user scenarios require somewhat different techniques than simpler single-user ones. People used to single-user development often tend to leave a lot of shared resources locked for long intervals by relying on default settings. In other cases they fail to lock such resources and then users' updates can step on each other. Concurrency is a topic all in itself.

Many people will choose to punt and choose another server-based database technology and let it try to sort out some of these issues itself.