I have an asp.net application in which I want to return a view based on the element found in my database. I use this code:
public static List<Event> events = new List<Event>();
public static int count = 0;
// GET: Events
public ActionResult Index()
{
_db = new ApplicationDbContext();
return View(_db.Events.ToList());
}
public ActionResult Details(int Id)
{
Event user = events.First(u => u.Id == Id);
return View(user);
}
[HttpGet]
public ActionResult Create()
{
return View();
}
[HttpPost]
public ActionResult Create(Event evnt)
{
if (evnt.Title == null || evnt.Title.Equals(""))
{
return HttpNotFound("Nu s-a gasit anplm");
}
_db = new ApplicationDbContext();
count++;
evnt.Id = count;
_db.Events.Add(evnt);
_db.SaveChanges();
return RedirectToAction("Index");
}
[HttpGet]
public ActionResult Update(int id)
{
Event user = events.First(u => u.Id == id);
return View("Create", user);
}
[HttpPost]
public ActionResult Update(Event user)
{
Event exisingUser = events.First(u => u.Id == user.Id);
exisingUser.Details = user.Details;
exisingUser.Title = user.Title;
exisingUser.DateAndTime = user.DateAndTime;
exisingUser.Location = user.Location;
return RedirectToAction("Index");
}
[HttpGet]
public ActionResult Delete(int id)
{
Event user = events.First(u => u.Id == id);
events.Remove(user);
return RedirectToAction("Index");
}
}
Here is the SQL:
CREATE TABLE [dbo].[Events] (
[Id] INT IDENTITY (1, 1) NOT NULL,
[Title] NVARCHAR (MAX) NOT NULL,
[Details] NVARCHAR (MAX) NULL,
[Location] NVARCHAR (MAX) NULL,
[DateAndTime] NVARCHAR (MAX) NULL,
[Image] NVARCHAR (MAX) NULL,
CONSTRAINT [PK_dbo.Events] PRIMARY KEY CLUSTERED ([Id] ASC));
And the model:
public class Event
{
public int Id { get; set; }
[DisplayName("Title")]
public string Title { get; set; }
[DisplayName("Details")]
public string Details { get; set; }
[DisplayName("Location")]
public string Location { get; set; }
[DisplayName("Date and Time")]
public string DateAndTime { get; set; }
public string Image { get; set; }
}
And I get this error: Error
I know that the First() returns null, but it shouldn't because I have the searched element in my database, I want it to find it. Please help!
It doesn't look like you are querying the database, try changing your Details action to
public ActionResult Details(int Id)
{
_db = new ApplicationDbContext();
Event user = _db.Events.First(u => u.Id == Id);
return View(user);
}
As per comment of @TetsuyaYamamoto.
You could consider using FirstOrDefault()
in your code to determine of there is a record existing in your list. It will return an object or null if record doesn't exist.
And of course, don't forget your DBContext
_db = new ApplicationDbContext(); //initialized dbcontext.
var user = _db.Events.First(u => u.Id == Id).FirstOrDefault();
if (user != null) {
return View(user);
}
else{
//do something to show no record found....
}
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