ASP.NET - ADO.NET DESCONECTADO

CREATE TABLE Producto

(

id INT IDENTITY(1,1) PRIMARY KEY,

idCategoria INT REFERENCES Categoria(id),

nombre NVARCHAR(50) UNIQUE,

precio DECIMAL,

enPromocion BIT,

tasaPromocion DECIMAL

)

public double PrecioPromedio()

{

    SqlConnection con = Bd.CrearConexion1();

    double aux= 0;

    SqlCommand cmd = new SqlCommand();

    cmd.Connection = con;

    cmd.CommandText = "select AVG(precio) as 'promedio' from Producto";

    cmd.CommandType = CommandType.StoredProcedure;

    SqlDataAdapter da = new SqlDataAdapter(cmd);

    return aux;

}

private static string cadenaConexion =

    ConfigurationManager

    .ConnectionStrings["conexionLC1"]

    .ConnectionString;

public static SqlConnection CrearConexion1()

{

    return new SqlConnection(cadenaConexion);

}

double aux = 0;

using (conn = Bd.CrearConexion1())

{

	using (SqlCommand cmd = new SqlCommand("SELECT AVG(precio) AS 'promedio' FROM Producto", conn)

	{

		aux  = cmd.ExecuteScalar();

	}

}