Creating a class for datamanipulation???

[zozzie]

Hi,

I have an application which is based on a MSAccess 2000 database with a number of related tables. The application contains some forms which have comboboxes and listboxes that need to give the related values from the tables.

Now I have in each form created a dataadapter and a dataset for each table I need in that specific form, but I think this produces a lot of overhead code. I was thinking about creating a class that I can reuse in every form. THe class should do the following:
- create a connection to a database
- create an oledbdataadapter
- create a dataset
- create a listbox that contains the value of the dataset

Is this possible? How do I have to programm this: do i need a windows form or a class? How can I use the class in the other forms?

I'm a newbie to OOP, so please give me some hints and a code example if possible?

Thank you very much for your time;

Tom

[Sheppe]

Originally posted by zozzie
Hi,

I have an application which is based on a MSAccess 2000 database with a number of related tables. The application contains some forms which have comboboxes and listboxes that need to give the related values from the tables.

Now I have in each form created a dataadapter and a dataset for each table I need in that specific form, but I think this produces a lot of overhead code. I was thinking about creating a class that I can reuse in every form. THe class should do the following:
- create a connection to a database
- create an oledbdataadapter
- create a dataset
- create a listbox that contains the value of the dataset

Is this possible? How do I have to programm this: do i need a windows form or a class? How can I use the class in the other forms?

I'm a newbie to OOP, so please give me some hints and a code example if possible?

Thank you very much for your time;

Tom

Yup, you can do this. Create a public class that contains public functions for everything that you wanna do. One thing to note, though, is that it is unneccessary to use a dataset for every table. One dataset can contain multiple tables.

The class would be something like:

Public Class DB
    Public Sub ConnectDB(ByRef CON As Connection)
        ' Notice that this is a sub that accepts an argument ByRef.
        ' Read up on passing arguments ByRef if you don't know
        ' what this does.
        '
        ' Enter DB connection code here.
    End Sub
 
    Public Function GetTable(ByVal CON As Connection) As DataSet
        ' Enter table retrieval code here.
    End Function
End Class

This is just off the top of my head, so it may have syntactical errors. Also, you'll have to add more functions/subs for everything that you wanna do.

HTH

[zozzie]

Thanks for your suggestion, I'll try it and I'll keep you informed.

Tom