Question

If i want to use Linq-SQL i also have to drag the DB Table unto the designer surface to create the entity classes.

I always like full control in my application and do not like the classes created by dotnet.

Is it possible to provide this connection between Linq and the DB using my own Data Access Layer Entity classes?

How can i get it done?

Answer 1

You can write your own classes very easily using Linq-to-SQL – just involves painting your classes with some Attributes.

For Example, this is a very simple table I have in one of my projects, and it works with Linq-to-SQL just fine:

[Table(Name = "Categories")]
public class Category : IDataErrorInfo
{
    [Column(IsPrimaryKey = true, IsDbGenerated = true, AutoSync = AutoSync.OnInsert)]
    public int Id { get; set; }
    [Column] public string Name { get; set; }
    [Column] public string ExtensionString { get; set; }
}

The code was very easy, especially if you make your property names line up with your table names (you don’t have to).

Then you just need a Repository to connect to the DB:

class CategoryRepository : ICategoryRepository
{
    private Table<Category> categoryTable;
    public CategoryRepository(string connectionString)
    {
        categoryTable = (new DataContext(connectionString)).GetTable<Category>();
    }
}

Of course there is more to it, but this shows you the very basics and it is not hard to do once you understand it. This way you have 100% control over your classes and you can still take advantage of Linq-to-SQL.

I learned this approach from Pro ASP.NET MVC Framework, an awesome book.

If you want to see more, all of my Linq-to-SQL classes were written from scratch on one of my projects you can browse here.