It's been a LONG time since my last programming "tutorial" so let's see how this goes.

When I was a noob (not like I am much of an expert now) I used to write code every time I wanted to connect to a database, as time went on I discovered the advantages of using classes and reusable functions or objects for repeatable tasks, like connecting to a database, and came up with a class named dbinterfase.

When to use it:

On middle to large projects I usually have a class for every table that the application will interact with and its in the methods of those classes that I create the dbinterfase object.

Example:

Very simple, clean and elegant. I have an equivalent class for PHP that I will be posting in a few days.

It’s not a good practice to return a SqlDataReader from a function, but, I like to do that because it’s easier to work with DataReaders than DataTables. Why is bad to return Data Readers? Because the object keeps a connection to the database open until the object gets destroyed or you close it manually.

Why I like to work with Data Readers?

Because the code looks more “readable” and the Data Reader acts more like a Recordset from the old ADO, but since the connection is always open while using a Data Reader it becomes a real pain in the ass if you need to open another connection to the database because at some point you could eat the entire connection pool. To avoid that I created a function that puts a SqlDataReader into a DataTable, and then another small function to convert the DataTable into a DataView. I could do it all at once, connect to the database and the function returns a DataView with all the information I want, BUT, I want my programs to be easy readable for when someone needs to maintain the code. I usually create a Class that contains all the Database functions I need so I don’t have to deal with Database Connection inside the core of the application. So, in order to have all the options I want from inside the class that has all the Database functions I created these two functions, one that converts into a DataTable a SqlDataReader and one that converts a DataTable into a DataView.

Then I create another function that returns the information I want, it goes something like this:

So when I need the list of new signatures (in this case) all I do is

I know, I know, the code could be faster if I just returned the DataView from GetNewSignaturesFromTable, but I like to have options when working with Tables, sometimes I use the same function for different purposes and those different purposes mean that sometimes I will use a DataTable and sometimes a DataReader, so I just return a reader, which is the common denominator, and deal with the rest with those functions.

While doing my first PocketPC application I came up with several problems, the first of them being how to connect to the internet using GPRS. I went to several forums only to find out that no one had a concrete solution, all of them pointed me to use the OpenNETCF Smart Device Libraries but none gave me an answer. So I just kept searching and looking on how that worked, compiled several lines of code from different sources and came up with my own GPRS Connection class for PocketPC. The code is not as polished as I want it to be, but it works.

Here are the first five libraries for Visual Basic.Net Compact Framework

• NetCF GPRS Connection
• NetCF Reset Device
• NetCF Power Status
• NetCF WIFI Power (WLAN Power)
• NetCF GSM Power (GPRS Radio Power)

If you follow the link you will find a brief explanation on how it should be used and a link to a zip file containing a [name].vb class file.