I have many to many relationship some tables. I am using entity framework.
Reservations >> ApartsToReservations << Aparts
ApartsToReservations include ReservationID and ApartID.
and my delete action below:
public ActionResult DeleteReservation(string resultId)
{
var result = Convert.ToInt32(resultId.Trim());
//just I have reservationID
return View();
}
How can delete reservation?
How can delete reservation?
For example:
[HttpPost] // <- should be a POST action because it's modifying data
public ActionResult DeleteReservation(string resultId)
{
var result = Convert.ToInt32(resultId.Trim());
//just I have reservationID
using (var context = new MyContext())
{
var reservation = new Reservation { ReservationID = result };
context.Reservations.Attach(reservation);
context.Reservations.Remove(reservation);
context.SaveChanges();
}
// ... redirect to Index or something, for example:
// return RedirectToAction("Index");
}
If you already have a context instance as a member of your controller class use this instead of creating a new one in the using block.
The code will also delete the related records in the ApartsToReservations link table because by default the relationships to this table are configured with cascading delete.
I'm not quite sure if this is what you are looking for because it actually doesn't matter if Reservation is involved in the many-to-many relationship you mentioned. It is just the (or one) standard way to delete an entity with DbContext.
If you are looking for something different please try to clarify your question or ask a new one which is clearer.
Related
I am trying to add a new record in an MVC controller method using Entity framework.
When i just used "InsertOrUpdate" the audittype got duplicated. Based on the answer from Entity Framework adding record with a related object i hoped to fix it pretty qiock. This is the code I have right now:
Controller:
if (ModelState.IsValid)
{
Audit newAudit = Factory.GetNew();
newAudit.Name = model.Name;
newAudit.Deadline = model.Deadline;
newAudit.AuditType = auditTypeRepository.Find(model.SelectedAuditTypeId);
Repository.InsertOrUpdate(newAudit);
Repository.Save();
return RedirectToAction(MVC.Audits.Details(newAudit.Id));
}
Repository:
public override void InsertOrUpdate(Qdsa.WebApplications.AuditMaster.Data.Audit model)
{
if (model.Id == default(int))
{
// New entity
context.Audits.Add(model);
}
else
{
// Existing entity
model.ModifiedOn = DateTime.Now;
context.Entry(model).State = EntityState.Modified;
}
//If I leave out the code below the AuditType will be duplicated
if (model.AuditType != null)
{
context.Entry<AuditType>(model.AuditType).State = EntityState.Unchanged;
}
}
public virtual void Save()
{
context.SaveChanges();
}
So i thought I fixed the problem. However, AuditType has Child objects too. And now these childobjects get duplicated.
What is the right way to add entities with child objects which already exists?
Because the AuditType is required I can't save it without first and then update it. any suggestions?
UPDATE:
Both the AuditRepostory and the AuditTypeRepository inherit from BaseRepository which has the context as:
protected DBContext context = new DBContext ();
public virtual T Find(int id)
{
return All.SingleOrDefault(s => s.Id == id);
}
I can imagine two reasons for the problem:
Either auditTypeRepository.Find performs a no tracking query (with .AsNoTracking())
Or you are using a context instance per repository, so that Repository and auditTypeRepository are working with two different contexts which will indeed result in a duplication of the AuditType because you don't attach it to the the context that corresponds with Repository (except in the line with your comment).
If the latter is the case you should rethink your design and inject a single context instance into all repositories instead of creating it inside of the repositories.
I think the problem is from here:
newAudit.AuditType = auditTypeRepository.Find(model.SelectedAuditTypeId);
Change that like this:
newAudit.AuditTypeId = model.SelectedAuditTypeId;
Im learning MVC 4. I have created a database first project using EF5. In my edit view I want to add a product number to a customer. When I hit save I get the message below. I think it is because product number is null in the product table, hence it cannot update. Can I get around this? I have added my edit control
public ActionResult Edit(int id = 0)
{
UserProfile userprofile = db.UserProfiles.Find(id);
if (userprofile == null)
{
return HttpNotFound();
}
//ViewBag.userId = new SelectList(db.Devices, "DeviceID", "DeviceIMEI", userprofile.UserId);THIS CREATES A NEW ENTRY IN USERPROFILE TABLE
ViewBag.Device_DeviceID = new SelectList(db.Devices, "DeviceID", "DeviceIMEI", userprofile.Device);
ViewBag.ShippingDetails_ShippingDetailsID = new SelectList(db.ShippingDetails, "ShippingDetailsID", "Address1", userprofile.ShippingDetails_ShippingDetailsID);
return View(userprofile);
}
//
// POST: /User/Edit/5
[HttpPost]
public ActionResult Edit(UserProfile userprofile)
{
if (ModelState.IsValid)
{
db.Entry(userprofile).State = EntityState.Modified;
db.SaveChanges();
return RedirectToAction("Index");
}
//ViewBag.userId = new SelectList(db.Devices, "DeviceID", "DeviceIMEI", userprofile.UserId);
ViewBag.Device_DeviceID = new SelectList(db.Devices, "DeviceID", "DeviceIMEI", userprofile.Device);
ViewBag.ShippingDetails_ShippingDetailsID = new SelectList(db.ShippingDetails, "ShippingDetailsID", "Address1", userprofile.ShippingDetails_ShippingDetailsID);
return View(userprofile);
}
"Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries"
It looks like you dont pass Id of UserProfile from
view to controller.
You should add
#Html.HiddenFor(model => model.Id)
to your form in view
You're posting a view model, which is disconnected from your entity framework, and trying to tell the EF that it has changed -- which it doesn't know about. Try something like this instead,
var obj = yourContext.UserProfiles.Single(q=>q.Id==userProfile.Id);
obj = userprofile; // ... Map userprofile to the tracked object, obj
yourContext.SaveChanges();
Try this:
if (ModelState.IsValid)
{
db.UserProfiles.Attach(userProfile);
db.SaveChanges();
return RedirectToAction("Index");
}
I'm looking at the single-page web application for MVC4 from VS templates (from here http://www.asp.net/single-page-application) and it looks like the PUT action for ToDoLists is creating a new ToDoList - why is this? The code from the DTO class definition:
public TodoList ToEntity()
{
TodoList todo = new TodoList
{
Title = Title,
TodoListId = TodoListId,
UserId = UserId,
Todos = new List<TodoItem>()
};
foreach (TodoItemDto item in Todos)
{
todo.Todos.Add(item.ToEntity());
}
return todo;
}
From the controller:
public HttpResponseMessage PutTodoList(int id, TodoListDto todoListDto)
{
TodoList todoList = todoListDto.ToEntity();
db.Entry(todoList).State = EntityState.Modified;
db.SaveChanges();
return Request.CreateResponse(HttpStatusCode.OK);
}
So to update a record, we create a new one? I'm a little confused about how this is working - any clarification would be awesome.
In this example, the controller is converting the TodoListDto object into a TodoList object, which is the database object type. Since the DTO object is coming back from the web page, it has to be changed into the appropriate type so that Entity Framework can attach it to the DbSet and save changes.
ToEntity doesn't actually create a new record in the database, it creates a new TodoList instance which then gets attached, as modified to the database.
When I update my model I get an error on a child relation which I also try to update.
My model, say Order has a releationship with OrderItem. In my view I have the details of the order together with an editortemplate for the orderitems. When I update the data the link to Order is null but the orderid is filled, so it should be able to link it, TryUpdateModel returns true, the save however fails with:
InvalidOperationException: The operation failed: The relationship could not be changed because one or more of the foreign-key properties is non-nullable. When a change is made to a relationship, the related foreign-key property is set to a null value. If the foreign-key does not support null values, a new relationship must be defined, the foreign-key property must be assigned another non-null value, or the unrelated object must be deleted.]
My update method:
public ActionResult ChangeOrder(Order model)
{
var order = this.orderRepository.GetOrder(model.OrderId);
if (ModelState.IsValid)
{
var success = this.TryUpdateModel(order);
}
this.orderRepository.Save();
return this.View(order);
}
I tried all solutions I saw on SO and other sources, none succeeded.
I use .Net MVC 3, EF 4.3.1 together with DBContext.
There are a number of code smells here, which I'll try to be elegant with when correcting :)
I can only assume that "Order" is your EF entity? If so, I would highly recommend keeping it separate from the view by creating a view model for your form and copying the data in to it. Your view model should really only contain properties that your form will be using or manipulating.
I also presume orderRepository.GetOrder() is a data layer call that retrieves an order from a data store?
You are also declaring potentially unused variables. "var order =" will be loaded even if your model is invalid, and "var success =" is never used.
TryUpdateModel and UpdateModel aren't very robust for real-world programming. I'm not entirely convinced they should be there at all, if I'm honest. I generally use a more abstracted approach, such as the service / factory pattern. It's more work, but gives you a lot more control.
In your case, I would recommend the following pattern. There's minimal abstraction, but it still gives you more control than using TryUpdateModel / UpdateModel:
public ActionResult ChangeOrder(OrderViewModel model) {
if(ModelState.IsValid) {
// Retrieve original order
var order = orderRepository.GetOrder(model.OrderId);
// Update primitive properties
order.Property1 = model.Property1;
order.Property2 = model.Property2;
order.Property3 = model.Property3;
order.Property4 = model.Property4;
// Update collections manually
order.Collection1 = model.Collection1.Select(x => new Collection1Item {
Prop1 = x.Prop1,
Prop2 = x.Prop2
});
try {
// Save to repository
orderRepository.SaveOrder(order);
} catch (Exception ex) {
ModelState.AddModelError("", ex.Message);
return View(model);
}
return RedirectToAction("SuccessAction");
}
return View(model);
}
Not ideal, but it should serve you a bit better...
I refer you to this post, which is similar.
I assume that the user can perform the following actions in your view:
Modify order (header) data
Delete an existing order item
Modify order item data
Add a new order item
To do a correct update of the changed object graph (order + list of order items) you need to deal with all four cases. TryUpdateModel won't be able to perform a correct update of the object graph in the database.
I write the following code directly using a context. You can abstract the use of the context away into your repository. Make sure that you use the same context instance in every repository that is involved in the following code.
public ActionResult ChangeOrder(Order model)
{
if (ModelState.IsValid)
{
// load the order from DB INCLUDING the current order items in the DB
var orderInDB = context.Orders.Include(o => o.OrderItems)
.Single(o => o.OrderId == model.OrderId);
// (1) Update modified order header properties
context.Entry(orderInDB).CurrentValues.SetValues(model);
// (2) Delete the order items from the DB
// that have been removed in the view
foreach (var item in orderInDB.OrderItems.ToList())
{
if (!model.OrderItems.Any(oi => oi.OrderItemId == item.OrderItemId))
context.OrderItems.Remove(item);
// Omitting this call "Remove from context/DB" causes
// the exception you are having
}
foreach (var item in model.OrderItems)
{
var orderItem = orderInDB.OrderItems
.SingleOrDefault(oi => oi.OrderItemId == item.OrderItemId);
if (orderItem != null)
{
// (3) Existing order item: Update modified item properties
context.Entry(orderItem).CurrentValues.SetValues(item);
}
else
{
// (4) New order item: Add it
orderInDB.OrderItems.Add(item);
}
}
context.SaveChanges();
return RedirectToAction("Index"); // or some other view
}
return View(model);
}
I have a Controller which returns a ViewModel to a View and it works just fine. I want to migrate to a Repository pattern but am having trouble getting the correct syntax in the repository. I have created the repository and the interface to it.
public interface IShippingRepository
{
IQueryable<ShippingCommHdr> All { get; }
IQueryable<ShippingCommHdr> AllIncluding(params Expression<Func<ShippingCommHdr, object>>[] includeProperties);
void InsertOrUpdate(ShippingCommHdr shippingcommhdr);
void Delete(int id);
void Save();
}
Here is the code form my Controller that I want to move to the repository:
public ViewResult ShippingSummary()
{
CPLinkEntities context = new CPLinkEntities();
var shipments =
from h in context.ShippingCommHdrs
where (h.CompletedDate == null)
join
e in context.vHr_Employees on h.CreatedBy equals e.ID
join
s in context.Shippers on h.ShipperID equals s.ShipperID
join
r in context.vAaiomsSites on h.ShipToSiteID equals r.SiteID
join
c in context.vHr_Employees on h.CreatedBy equals c.ID
join
p in context.vHr_Employees on h.FromSitePOC equals p.ID
select new
{
h.ID,
ShippedToSite = r.SiteName,
h.DateShipped,
h.EstDeliveryDate,
h.TrackingNo,
h.HeaderComments,
h.ShippingCommLI.Count,
s.Shipper,
CreatedBy = c.LastName,
FromSitePoc = p.LastName
};
var model = new List<ShippingSummaryVM>();
foreach (var h in shipments)
{
var viewModel = new ShippingSummaryVM
{
ID = h.ID,
ShippedToSite = h.ShippedToSite,
DateShipped = h.DateShipped,
EstDeliveryDate = h.EstDeliveryDate,
TrackingNo = h.TrackingNo,
FromSitePOC = h.FromSitePoc,
Shipper = h.Shipper,
HeaderComments = h.HeaderComments,
NumOrders = h.Count,
CreatedBy = h.CreatedBy,
};
model.Add(viewModel);
}
return View(model);
}
If I could get this one Controller/Repository to work, I can then migrate all the others over fairly quickly. thanks for any assistance
I'd start by adding a method definition to the repository interface for the query you need to execute. The repository can give this query a meaningful name:
public interface IShippingRepository
{
IQueryable<Shipment> GetShipments()
// ...
}
In the controller you'll need an instance of the repository. You can inject it into a constructor, or create one in a constructor, but either way the repository will need to talk to the CPLinkEntities context behind the scenes. You'll need to pass a context into the repository for the repository to work with.
public class SomeController : Controller
{
IShippingRepository _shippingRepository;
public SomeController()
{
_shippingRepository = new ShippingRepository(new CPLinkEntities());
}
public ViewResult ShippingSummary()
{
var shipments = _shippingRepository.GetShipments();
// ....
}
}
A concrete repository definition might look like the following.
public class ShippingRepository : IShippingRepository
{
CPLinkEntities _entities;
ShippingRepository (CPLinkEntities entities)
{
_entites = entities;
}
public IQueryable<Shipment> GetShipments()
{
return from ship in _entities.Ships join ... join ... select
}
}
Your controller method basically has 2 responsibilities
Run a Query
Map the results of the query into a view model
You can put that query into a repository, and then you could use an auto-mapper tool like AutoMapper or ValueInjecter to help you map the results of your query to a view model.
Your resulting controller method would simply call the repository to get a list of CPLinkEntities. Your controller method could then take those entities and then call the automapper to give you a list of ShippingSummaryVM's. I've left some implementation details, but this should give you a high level understanding of how to achieve what you are asking.
Option A: Have a stronger domain model. Your repository would responsible for loading root level domain objects and you let the underlying OR/M handle object traversal. Your controller would call a method on shipment to find shipments that are not yet completed. You'd get back a shipment object and could traverse to the related entities to get site name and other details you need for your VM
Option B: Have repositories that return all for each entity, and then do the join in a business or service layer. Entity Framework won't load all even if you say ShippingRepository.All. It only loads at the last responsible moment (when you need a materialized result). So you could have a business method that joins the "All" on each entity and filters based on completed date then returns back the result.
Option A is better but might be a lot more work.