Question

I have an old app that I’m supporting and I ran across the following Shared SQLConnection:

    private static SqlConnection cnSQL = new SqlConnection(ConfigurationManager.ConnectionStrings["SQL"].ConnectionString.ToString());
    private static SqlCommand cmdSQL = new SqlCommand();

Now this connection is opened and closed everytime it’s needed, but it still get a sporatic error, and I believe this is because its being shared accross users (being static). Is my assumption correct? I believe I am much better off creating a new connection inside each method that needs it instead of having one per class. Or can I just remvoe the static option, and keep one connection per page and not have to worry about cross user contamination?

Thanks

Answer 1

Static members are shared between all the objects and methods of your code in the actual instance of your application but in no case between different users.

I would make the connection string static but not the connection itself. As you say, open a new connection in each method. Connection pooling will ensure that the physical connections will be kept open.

public static readonly string ConnectionString connString =
    ConfigurationManager.ConnectionStrings["SQL"].ConnectionString.ToString();

…

private void SomeMethod()
{
    using (var conn = new SqlConnection(connString)) {
        string sql = "SELECT ...";
        using (var cmd = new SqlCommand(sql, conn)) {
            ...
        }
    }
}

Make sure you are embedding the code in using-statements. That way Resources are released even when an exception should occur.