Question

I’ve been a bad programmer because I am doing a copy and paste. An example is that everytime i connect to a database and retrieve a recordset, I will copy the previous code and edit, copy the code that sets the datagridview and edit. I am aware of the phrase code reuse, but I have not actually used it. How can i utilize code reuse so that I don’t have to copy and paste the database code and the datagridview code.,

Answer 1

Depending on the size of the project can change the answer.

For a smaller project I would recommend setting up a DatabaseHelper class that does all your DB access. It would just be a wrapper around opening/closing connections and execution of the DB code. Then at a higher level you can just write the DBCommands that will be executed.

A similar technique could be used for a larger project, but would need some additional work, interfaces need to be added, DI, as well as abstracting out what you need to know about the database.

You might also try looking into ORM, DAAB, or over to the Patterns and Practices Group

As far as how to prevent the ole C&P? – Well as you write your code, you need to periodically review it, if you have similar blocks of code, that only vary by a parameter or two, that is always a good candidate for refactoring into its own method.

Now for my pseudo code example:

Function GetCustomer(ID) as Customer    Dim CMD as New DBCmd('SQL or Stored Proc')    CMD.Paramaters.Add('CustID',DBType,Length).Value = ID    Dim DHelper as New DatabaseHelper    DR = DHelper.GetReader(CMD)    Dim RtnCust as New Customer(Dx)    Return RtnCust End Function  Class DataHelper   Public Function GetDataTable(cmd) as DataTable     Write the DB access code stuff here.     GetConnectionString     OpenConnection     Do DB Operation     Close Connection   End Function   Public Function GetDataReader(cmd) as DataReader   Public Function GetDataSet(cmd) as DataSet   ... And So on ... End Class