Hi there

How many users can connect to the different types of databases, for example Access, Oracle, SQL etc?

I have a database application that I want to write. The amount of users could be anything from 1 to 100. Obviously data integrity is important, especially the larger the amount of users simultaneously accessing the database.

Thank you!
dwsteyl

Hi,
There are 2 differnt connection concepts here.
1. Concurrent (at the same time)
2. non-concurrent (one user at a time)

All databases support unlimited(?) non-concurrent access.

For real physicial concurrent access (ie. actual connections from the user's software to the sql box):
Access about 10
Oracle/SQL about 2 million (then things start getting tricky).
MSDE up to 100 (i think)

Note.
Concurrent access is more than just buying a big machine and sticking a database server on it, there are coding considerations like locking, cursors, etc.

All of the systems you mention support relational integrity, however "data integrity" is a concept and not a physical thing.
For example,
You are storing an addess, and the user keys in your name first, then adds a few different the address details (delivery/shipping address, invoice address, etc.).
The database can enforce the rule that you must have a name before you have an address, however, it cannot enforce the correctness of the data (living on Mars is probably not real).

Also,
Do they really need 100 connections, most users sit there on a screen for a while before clicking Save - so you can probably get away with them not connected directly for updates.
Most applications connect, read, then disconnect immediately.

You need to seriously consider the above issues for a project like this.

I would suggest you start with Access, then upgrade, especially if this is your first database system.
The other "grown-up" database (Database Management Systems - DBMS's) require you to understand tables, views, procs, functions, packages, etc. and a whole load of stuff to deal with concurrent access and transactions.

How do you intend to connect to your database? In access you have no problem, however, with VB you'll need to handle connectinos yourself - it's not hard, just another detail before you even get your app working

If you provide some details of your application we may be able to suggest the "best" ways to go fwd.

Hope this helps,
Kieron


____________________________
Build it better, faster, quicker, easier.. then fix it (non-offical MS mission statement)

Kieron

Thank you for your reply. That was the most straight forward answer I've received so far!

I work at an audit firm. We do income tax and VAT for our clients, as well as annual financial statements. In total we have approximately 600 clients. Of those we have to submit almost 100 returns for VAT purposes every 2 months and of course a tax return for each customer once a year. Of course there are a few smaller returns that need to be submitted as well, but that small change.

As of yet there is no application (that I know of) that keeps record of which return is ready for submission / has been submitted. That might sound strange with a client base that big. We have almost 25 people, and if you divide the clients up between them, is manageable.

The following problem arises: When I want to know whether a return has been submitted for a particular client for a particular period, I have to ask the responsible person or look in the customer's file myself. As you can imagine, that becomes frustrating.

What I want to write is a database application that is relatively easy in concept. It would have a table for the usual name, address etc. Then it would have a table for each VAT period (12 in total), one for the annual returns and so forth.

When I load the data into a grid, it needs to get the client name and reference number from the client table, as well as the relevant period's info from the relevant VAT table, for example. I then need multiple checkboxes in the grid, on which our staff can click if that action has been done, whether it may be that the return has been submitted etc. Of course that would then be available to all workstations, if they log in to the program and view the specific periods data.

I do not need to see each client individually. All the info can be displayed in a grid. If the specific return has been clicked as submitted, that specific row in the grid should be green. This would of course be done via code.

That is the program in a nutshell.

I want to test this out on my own. I do not have a budget for this.

I program in VB6 in my spare time. Although I know VB farely well, I have absolutely no experience with databases. At the moment I'm going through a VB6 database book of John Smiley. Interesting material, but they focus mainly on DAO and a little bit on ADO. As far as I know, I should at least use ADO. I do have Access 2000.

This was a mouthful. Any suggestions?

HI
Just to let you know, i'll do you a sample asap.
Access is the way forward with this one, IMO.
You can still prcatice your VB(albeit in VBA).

I'll get back to you asap.
Kieron


____________________________
Build it better, faster, quicker, easier.. then fix it (non-offical MS mission statement)

Hi
Still unable to produce db, as my great flashy new pc no longer has access  
But.
Break your problem down into chunks and post the questions that you have to the forum.

Example:
I need a database to do this:
a
b
c
d
Each requirement/point must have a title no longer than 80 characters, with a description as long as you want.
Take each noun - this is a candidate for a table (client, address, tax return,  vat period, etc.) and add a field to it for the key (ie. AddressID, ClientID, TaxREturnID, etc.), and additional fields for the data to hold.

Don't worry about flashy colours and so forth just yet.

Once you've got your tables and the above details done, post it back up with specific questions (how do i get a form to turn green for a particular record), etc.

Hope it helps,
Kieron



____________________________
Build it better, faster, quicker, easier.. then fix it (non-offical MS mission statement)