ASP. net mvc learning Summary (2)

Not long ago, I learned the webform of asp.net before learning MVC. I felt that thinking had changed a lot and I couldn't help using webform, so I forgot something about webform, start from scratch to understand MVC3.0. Below is a simple start.

In asp.net's webform, if you want to write, you will write a lot of SQL statements, such as INSERT INTO TABLE (), SELECT ..... In short, it is necessary to write a large number of SQL statements, especially in complex paging SQL statements. If the statements are not well written, there will be some inintention errors, let's take a look at how to add, delete, query, and modify MVC3.0:

(1) Add data with the following code:

 1   public ActionResult Create(User dpt) 2         { 3             var data = db.Departments.OrderByDescending(p => p.Name); 4             ViewBag.DptName = data; 5             try 6             { 7                 db.Entry(dpt).State = System.Data.EntityState.Added; 8                 db.SaveChanges(); 9             }10             catch (Exception ex)11             {12                 ViewBag.Ex = ex.Message;13             }14 15             return View();16         }

Let's take a look at the colored code in the code. It's simple enough. It's so simple. Do you want to write SQL statements after reading it? Are you still writing a lot of "redundant code" to get data from the foreground? Try it!

(2) Let's take a look at the deleted code. You don't need to write such as DELETE .. The Code is as follows:

1   public ActionResult Delete(string LoginName)2         {3             User users = new User();4             users.LoginName = LoginName;5             db.Entry(users).State = System.Data.EntityState.Deleted;6             db.SaveChanges();7             return RedirectToAction("Index", new { id = Request.QueryString["page"] });8         }

(3) The data list Code is as follows:

 1  public ActionResult Index(int? id) 2         { 3             var list = from p in db.users.Include(p => p.Department) orderby p.ID descending select p; 4             IEnumerable<User> data = list.ToPagedList(id ?? 1, 5); 5             if (Request.IsAjaxRequest()) 6             { 7                 return PartialView("_Index", data); 8             } 9             else10             {11                 return View("Index", data);12             }13         }

How about it? Are you still worrying about complex code like paging SQL for data on the list page? Don't hesitate. Please try it, but ToPagedList (id ?? 1, 5); It is implemented. It is not included in the actual MVC3.0. Next time, we will provide a method that does not use the implemented code, summary .........