VB4 : The DAO Strikes Back

by Ross Mack - GUI Computing

Letís review some of the history of Visual Basic for a moment.

VB 1.0 was now quite a while ago, but at the time it revolutionised the way people thought about Windows development - at least it would have if more people had taken it seriously. VB 2.0 showed that it was probably here to stay and it started to pick up a lot of third party support (remember when Approach wasnít owned by Lotus and was a VB 2.0 add on ?). Around this time Access 1.0 was released and then Access 1.1 shortly after that. Thus began the first trickles of what was to become the Windows database market deluge.

We were then treated to a new version of an increasingly accepted and supported programming tool that had the database engine of Access built in, VB 3.0. This was way cool. Then Access 2.0 came out and the issues became confused again. We needed a compatibility layer to talk to the new Jet engine from VB. But it worked and the compatibility problems were minor. Which brings us to VB 4.

One of the really cool things about VB 4 is that it is again synchronised with the Jet database engine. VB expects the engine to work how it does work. You will also find, fellow thrill-seekers, that VB is working with the latest Jet engine. That is version 2.5 on 16 bit systems (Win 3.1x) and Jet 3.0 on 32 bit systems (Win 95 and NT). The 32 bit implementation also has 32 bit ODBC. Thatís something we can all dance to.

All that, however, is all well and good but leaves us still waiting for the punch-line. VB 3.0 gave us a cut down view of the Jet engine object hierarchy. The top of the hierarchy as far as we could see in VB 3.0 was the Database object. There was also no access to security objects. With VB 4.0 this has all changed. Now the whole Jet object hierarchy is exposed to us to use freely in VB code.

Let's take an example.

Written by: Ross Mack
Aug 95