cleanest way to access sproc data in asp.net - asp.net

Question

I haven't accessed data using SqlCommand etc. for a while as I tend to use NHibernate these days. I am just wondering whether the following code could be improved. I have tried to use best practises (after some google-ing) and potential exceptions are caught at a higher layer.
[WebMethod]
public XmlDocument GetClassRegistrationReport()
{
XmlDocument doc = new XmlDocument();
using (SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["bla"].ToString()))
{
using (SqlCommand command = connection.CreateCommand())
{
command.CommandText = "bla";
command.CommandType = CommandType.StoredProcedure;
connection.Open();
doc.Load(command.ExecuteXmlReader());
}
}
return doc;
}
Thanks!
Best wishes,
Christian

Answer 1

There are a few ways you could improve it a little:
Although the WebMethod pulls data and returns it verbatim with no input parameters, I would suggest seperating service interface and the data into seperate classes. It may make things easier to maintain at a later date.
Assuming there are other DB calls in your framework you may want to consider a helper method in your data layer that wraps up the invocation of a stored procedure. This way you only have one method that all SP calls filter down into which again will make things easier to maintain in the future.
Make the 'bla' key for your connection string setting a constant, this way you can easily reuse and change.
The same applies to the name of the stored procedure, alternatively make it part of your web.config - this means you can change the stored proc name without having to recompile.
If an exception is throw there is no handling for this so the exception will bubble out to the caller, consider catching and handling/logging exceptions. That said you do mention that you are handling exceptions at a higher layer, so I assume this is being done in whatever is calling your webservices.
You should be disposing the SQL command object (in the finally of the try/catch/finally if you do implement exception handling)
EDIT : Code Sample
public class MyWebService
{
[WebMethod]
public XmlDocument GetClassRegistrationReport()
{
return DataLayer.GetClassRegistrationReport();
}
}
// Notice that this is a static internal class, internal to hide the
// data access class from everything but this library and static because
// we don't need instances and using statics will optimise a little.
internal static class DataLayer
{
private const string SP_GetRegistrationReport = "GetRegistrationReport";
private const string Config_DBConnectionString = "PrimaryDB";
private static string GetDB
{
get
{
string dbConnectionString = ConfigurationManager.ConnectionStrings[Config_DBConnectionString].ConnectionString;
if (string.IsNullOrEmpty(dbConnectionString))
{
// This error should could/should be in a resource file.
throw new ConfigurationException("Database connection string is not defined");
}
return dbConnectionString;
}
}
internal static XmlDocument GetClassRegistrationReport()
{
XmlDocument doc = new XmlDocument();
using (SqlConnection connection = new SqlConnection())
{
using (SqlCommand command = connection.CreateCommand())
{
command.CommandText = SP_GetRegistrationReport;
command.CommandType = CommandType.StoredProcedure;
connection.Open();
doc.Load(command.ExecuteXmlReader());
}
}
return doc;
}
}