My Practices coding

namespace LINQtoSQL
{
public partial class PublisherMgr : System.Web.UI.Page
{
Table tbPublisher;
DataContext publisherDataContext;
protected void Page_Load(object sender, EventArgs e)
{
SqlConnection conn = new SqlConnection(DataAccess.GetAdventureConnection());
publisherDataContext = new DataContext(conn);
tbPublisher = publisherDataContext.GetTable();
gvPublisher.DataSource = from pub in tbPublisher orderby pub.PublisherName select pub;
gvPublisher.DataBind();
}
protected void btnSave_Click(object sender, EventArgs e)
{
Publisher newPub = new Publisher();
newPub.PublisherId = Guid.NewGuid();
newPub.PublisherName = txtPublisher.Text;
tbPublisher.InsertOnSubmit(newPub);
publisherDataContext.SubmitChanges();
gvPublisher.DataSource = from pub in tbPublisher orderby pub.PublisherName select pub;
gvPublisher.DataBind();
}
}
}



namespace LINQtoSQL
{
static public class DataAccess
{
static public IQueryable GetDataAccess()
{
string connectionString = ConfigurationSettings.AppSettings["connectionString"].ToString();
SqlConnection connection = new SqlConnection(connectionString);
DataContext dataContext = new DataContext(connection);
IQueryable books = from book in dataContext.GetTable() select book;
return books;
}
static public string GetAdventureConnection()
{
return ConfigurationSettings.AppSettings["connectionString"].ToString();
}
static public string GetNorthwindConnection()
{
return ConfigurationSettings.AppSettings["connectionStringNorthwind"].ToString();
}
}
}


namespace LINQtoSQL
{
[Table(Name="dbo.Book")]
public class Book
{
[Column(Name="BookId", IsPrimaryKey=true)]
public Guid BookId { get; set; }
[Column(Name="Isbn")]
public string Isbn { get; set; }
[Column (Name="Notes")]
public string Notes { get; set; }
[Column(Name="PageCount")]
public Int32 PageCount { get;set; }
[Column (Name="Price")]
public decimal Price {get;set;}
[Column (Name="PublicationDate")]
public DateTime PublicationDate { get; set; }
[Column (Name="Summary")]
public string Summary{get;set;}
[Column (Name="Title")]
public string Title{get;set;}
[Column (Name="SubjectId")]
public Guid SubjectId { get; set; }
[Column (Name="PublisherId")]
public Guid PublishId { get; set; }
}
[Table(Name = "dbo.Subject")]
public class Subject
{
[Column(Name="SubjectId",IsPrimaryKey=true)]
public Guid SubjectId { get; set; }
[Column(Name="Description")]
public string Description { get; set; }
}
[Table(Name = "dbo.Publisher")]
public class Publisher
{
[Column(Name="PublisherId", IsPrimaryKey=true)]
public Guid PublisherId { get; set; }
[Column(Name="PublisherName")]
public string PublisherName { get; set; }
}
}