Question

I’m designing a web service in ASP.NET and VS2008, and am using typed datasets for retrieving table data. These work well and establish their own connections through their associated TableAdapter objects. Edit: I’m using VB, BTW!

I am now attempting to run a custom SQL string using a DataAdapter and a Command object, however I need to reference a Connection object in order for the Command to work. What is the best way to handle this? Should I:

a) Create a global connection object using Global.asax, retrieving the connection string from web.config? (I’ve been trying that one already, with not much success)

b) Create a class-level connection object using the InitialiseComponent method, also retrieving the ConnectionString from web.config?

c) Retrieve a Connection from one of the TableAdapters that I’ve already created in my typed DataSets?

d) Something else I haven’t thought of yet?

BTW I’ve been finding it very difficult to extract a ConnectionString from web.config, so any help with that would be appreciated also!

I’m not entirely inexperienced with ASP.NET, but my last big project used VS2003, and I want to make sure that I’m using the current tools correctly.

Answer 1

To extract the connection string, use

WebConfigurationManager.ConnectionStrings["name"].ConnectionString

It’s best to open and close the connections as close as possible to their use. ADO.NET will do connection pooling so that this won’t be expensive:

var connectionString = 
    WebConfigurationManager.ConnectionStrings["name"].ConnectionString;
using (SqlConnection conn = new SqlConnection(connectionString))
{
    using (SqlCommand cmd = new SqlCommand("query", conn))
    {
        conn.Open();

        // Use the command
    }
}