backend change

[bobbytom]

dear friends

i am planning to make an inventory multiuser package with vb and access 2000 now. after some time we have to change the backend to sql server or oracle. So what are the precautions i have to take before writing the code in vb with Access. can i use autoincrement column as P.K

bobby

[Bill Crawley]

Upgrading from Access to SQL shouldn't be too much of an issue, since the underlying engine is basically the same.

If your upgrading to Oracle, there may be issues with numeric data types especially the larger ones such as double. Date and time fields are also different and any SQL that you may have using date and time functions will need to be looked at (date and time in SQL Server will need to be looked at to).

If your VB currently has a lot of 'Select * from.....' statements, Depending on which verson of Oracle you are using and the data providers, you may notice that you get NO records returned, this will be because you need to be explicit in the columns that you want returned (i.e. name them).

All these databases have an autoincrement feature, however I personally do not like to rely on that for primary keys. It's much better to have control of them. (Just a personal preference).

If you know your going to upgrade later, place all your ACCESS SQL into a single class module or similar and NOT all over the place, then when you go to upgrade, you only need to change code in one place, since you'll probably want to use some of the extra features that are offered by SQL Server or Oracle.

Locking types are also different between Oracle and SQL Server, so be careful there to.

I think these cover the general problems, the rest will come as you work your way through the code.

[Twodogs]

Your biggest problems will be with dates & integers. Other than that, any sql statements that use joins should be looked at to make sure that you're going to be getting what you really want.

[bobbytom]

thanks friends for ur valuable information. i will take care while writing code. anything more please?

bobby