Re: Architecture ideas for n-tier app with diff backends

You may want to try using OpenLink's ODBC drivers. Please visit http://www.openlinksw.com if you are interested. Since most major database engines are supported, it would supplant the need for individual drivers for each backend database.

General Information:

High-Performance 16 & 32 Bit Generic ODBC Drivers that provide transparent access to remote databases from ODBC compliant Desktop Productivity Tools (Spreadsheets, Word Processors, Presentation Packages, Desktop Databases, Personal Organizers), Client-Server Application Development Environments, Web based Database Publishing Tools, and Computer Telephony Integration packages, etc.

Features:

• ODBC 1.0 - 3.0 Compatible
• ODBC Core, Level 1, Level 2, and Extensions support
• Server based Scrollable Cursor Support - Cursors are server based
• In-built Database Independent Communications Layer
• 32 Bit Drivers are usable by 16 Bit ODBC compliant applications
• Sophisticated Data security via Encryption.
• Concurrent access to heterogeneous data sources (via OpenLink Database Agent)
• Centralized File Data Source Name support (one ODBC Data Source serving all remote ODBC Clients).

Operating Systems Supported:

Windows 3.11/95/NT, Solaris, SunOS, HP-UX, AIX, IRIX, DG-UX, SINIX, Generic UNIX 5.4 (AT&T), Unixware, SCO UNIX, Linux, MKLinux, BSDI Unix, NetBSD, FreeBSD, flavors, OpenVMS, Vax/VMS, OS/2, MacOS.

Databases Supported:

Oracle, Microsoft SQL Server, DB/2, Informix, Progress, CA-Ingres and other ODBC compliant database engines.

--
Thanks,

Edward A. Geddis
Technical Support Consultant
OpenLink Software
http://www.openlinksw.com
Making Technology Work for You

Rob Simpson <rob_at_soltec.demon.co.uk> wrote in message news:wRQHMIA2h6c3IArY_at_soltec.demon.co.uk...
> We are a small software house specialising in DTB APPS with database
> engines and have come up with plans similar to the ones above, but with
> slight differences. This is our interpretation of the (largely acedemic,
> Dont Get Bogged Down!!!) argument. I use a "Customers MAintenece"
> example to illustrate terms.
>
> Presentation Layer
> ------------------
>
> Responsible for displaying data and accepting user input. ie, accepts
> new customer details
>
>
> WorkFlow Layer
> --------------
>
> This is the so-called business objects layer, containing validation
> rules and business processes. It also calls the standard functions in
> the Database Driver in the sequence and logic needed to complete a
> transaction. For example, here is the vb-(ish) psudo code for an "add
> new customer" routine.
>
> std.GetCustomer (newcustID)
> IF [Customer Exists]
> Raise Error "Customer Already Exists"
> Else
> std.AddCustomerRecord(Customer Details.......)
> Endif
> If [Records Effected] = 1 then
> [Everything OK]
> else
> Raise Error " Addition Failed"
> Endif
>
> Database Driver
> ---------------
>
> These are set routines to perform certain "indivisable Business
> Transactions" such as GetCustomer, AddCustomerRecord, delete customer
> etc, that may or may not return disconnected ADO recordsets. Mostly they
> consist of routines to build SQL statements and pass them to the
> Database engine. It is compiled as a separate DLL for interchangability
> as the database engines accept different dialects of SQL. For example,
> there may be a driver for SQL, Access, oracle etc.
>
>
>
> I hope this is some use, or even better, somebody comes up with a major
> flaw in it (it would save us a major re-write!!!), any comment or
> criticisms welcome)
>
> Cheers
> _
> ROB dd
>
>
> --
> Rob Simpson
Received on Thu Jul 01 1999 - 12:14:41 CDT