So, I have a problem in save data which contains related entities, when I save it a new relation blank is created.
Exemple:
Entities:
public class Project
{
public int Id { get; set; }
public int Code{ get; set; }
public string Description{ get; set; }
public virtual Client Client { get; set; }
}
public class Client
{
public int Id { get; set; }
public int Code { get; set; }
public string Name { get; set; }
}
The Controller GET:
public ActionResult Create()
{
PopulateDropDownClienteList(String.Empty); //Returns to ViewBag to create a combobox .in view
return View();
}
The View:
#Html.DropDownListFor(m => m.Client.Id, new SelectList(ViewBag.Client_Id, "Id", "Name"), new { Name = "Client.Id" });
The Controller POST:
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create(string command, Project project)
{
try
{
if (ModelState.IsValid)
{
projectRepository = new ProjeRepository();
Project pro = projectRepository.ReturnByCode(project.Code);
if (pro == null)
projectRepository.Save(project);
else
projectRepository.Update(project);
PopulateDropDownClienteList(String.Empty);
Return View();
}
else
{
return View(project);
}
}
catch (Exception ex)
{
return View();
}
}
So when I save the data, the client is not associated with the project. just creating a new blank Client.
You Project Save code is not updating the entity, it is ADDING a new one all the time.
You should have update logic similar to following grounds -
To Add new FK Entry and associate it with parent record -
var entity = entities.Students.Where(p => p.Id == "2").First();
entity.StudentContact = new StudentContact() { Contact = "xyz", Id = "2" };
entities.Students.Attach(entity);
var entry = entities.Entry(entity);
// other changed properties
entities.SaveChanges();
To update a FK record with new details -
var entity = entities.Students.FirstOrDefault();
entity.StudentContact.Contact = "ABC";
entities.Students.Attach(entity);
var entry = entities.Entry(entity);
entry.Property(e => e.StudentContact.Contact).IsModified = true;
// other changed properties
entities.SaveChanges();
The above code, I have a Student records which has FK relationship with StudentContacts. I updated Contact information of a student and then updated it to database using ATTACH.
You've got a number of issues here, so let me break them down.
First and foremost, do not ever catch Exception (at least without throwing it again). There's two very important things about using try...catch blocks: you should only wrap the code where you're expecting an exception (not nearly your entire method as you've done here), and you should only catch the specific exception you're expecting (not the base type Exception). When you catch Exception, any and every exception that could possibly be generated from your code will be caught, and in this case, simply discarded, which means you really will never know if this code works at all.
Second, you have a fine method that generates a dropdown list of choices, but never store the user's selection anywhere meaningful. To understand why, you need to stop and think about what's happening here. An HTML select element has a string value and a string text or label component. It does not support passing full objects back and forth. I can't see what your PopulateDropDownClienteList method does, but what it should be doing is creating an IEnumerable<SelectListItem>, where each item gets its Text property set to whatever you want displayed and its Value property to the PK of the Client. However, once you have that, you need some property on Project to post back to. Your virtual Client won't work as that needs a full Client instance, which your form will never have. So, you have two choices:
Implement a view model to feed to the view (and accept in the post). In that view model, in addition to all other editable fields, you'll include something like ClientId which will be an int type, and you'll bind this to your drop down list. Once you're in your post method, you map all the posted values to your project instance, and then use the ClientId to look up a client from the database. You then set the resulting client as the value for your Client property and save as usual.
You alter your database a bit. When you just specify a virtual, Entity Framework smartly creates a foreign key and a column to hold that relationship for you behind the scenes. That's great, but in situations like this, where you actually need to access that foreign key column, you're screwed. That way around that is to explicitly define a property to hold that relationship on your model and tell Entity Framework to use that instead of creating its own.
[ForeignKey("Client")]
public int ClientId { get; set; }
public virtual Client Client { get; set; }
With that, you can now directly use ClientId without worrying about filling in Client. You again bind your drop down list to ClientId, but now, you do not need to look up the client explicitly from the database. Entity Framework will just save the ClientId as it should to the database, and then restore the Client based on that when you look up the project again in the future.
Related
I have a view in my DB. I have created model of view and call it with EF Core. There are 16 rows in view. When I call it with EF Core and use Take(10) it returns 10 rows but I look DBSet all rows shows there. For detail here is my code
[Table("my_view", Schema ="dbo")]
public class MyView
{
[Column("id")]
[Key]
public int Id { get; set; }
[Column("name")]
public string Name { get; set; }
}
in my action:
public JsonResult Index()
{
using (var context = new CCContext())
{
var listOfData = context.MyView
.AsQueryable().Take(10).ToList();
return Json(listOfData);
}
}
PS. For some problem I couldn't upload screen of result.(https://m.imgur.com/gallery/xmP3q32)
https://imgur.com/a/xmP3q32
If you mean context.MyView contains all rows, then you are right. Because that is a representation of the table in the DB. However, in your example listOfData should contain only 10 rows. If so, then this is as it should be expected.
If the above does not answer your question, please give some more insight and also, what DB provider are you using with EF?
For clarification:
The data is not there untill you ask a debugger (or code) to fetch it for you. The only reason you see it is because you ask the debugger to show its contents, and therefor it fetches its contents. It wont if you wont ask it to.
EDIT-2: After hours of research and almost every odata related link on google turning purple, I found out that the concept of 'deep-inserts' (link) exists in the OData specification. So after all, what I'm doing should work, even without the links. Does anyone know how to enable this on the Microsoft OData client? Are there any other OData clients out there that support that concept?
EDIT: Maybe this is the wrong approach, so please tell me if I'm doing it totally wrong. Not being able to save is really blocking our progress!
I have an issue with OData v3. I have a class Associate that has a required Address. When I try to POST a new Associate, it fails due to the Address property being null (EF6 throws DbUpdateException with foreign key violation). My Associate class looks like this:
public class Associate
{
public int Id { get; set; }
[Required, StringLength(100)]
public string Name { get; set; }
[Required, StringLength(50)]
public string Role { get; set; }
public bool IsMailReceiver { get; set; }
public bool IsLegalRepresentative { get; set; }
[ForeignKey("AddressId")]
public virtual Address Address { get; set; }
public int AddressId { get; set; }
}
I use the Microsoft OData client, and try to add the associate in the following way:
var associate = new Associate { /* ... */ };
context.AddObject("Associates", associate);
context.AddObject("Addresses", associate.Address);
/* UI fills associate data */
context.SetLink(associate, "Address", associate.Address);
context.UpdateObject(associate);
context.UpdateObject(associate.Address);
/* at this point the associate has the address set! */
context.SaveChanges(); // << Exception
On the server, in the controller, the Associate arrives without the foreign key, however. When I inspect the POST request with Fiddler, I see why:
{
"odata.type" : "xxx.Data.Entities.Associate",
"AddressId" : 0,
"Id" : 0,
"IsLegalRepresentative" : false,
"IsMailReceiver" : false,
"Name" : "John Doe",
"Role" : "Father"
}
The address is not transmitted, even though the generated class on the client has an Address property.
How can i solve this problem?
I too could not find any information about this - it really feels like an issue in OData. Here is how I managed to get it to work.
Define the foreign key explicitly
class Student {
public int TeacherId { get; set; }
[Required, ForeignKey("TeacherId")]
public virtual Teacher Teacher { get; set; }
}
When performing the insert, fetch the related record and fix the model state:
public IHttpActionResult Post(Student student)
{
student.Teacher = this.db.Teacher.FirstOrDefault(i => i.TeacherId == student.TeacherId);
if (student.Teacher != null)
{
this.ModelState.Remove("student.Teacher");
}
if (!this.ModelState.IsValid)
{
return this.BadRequest(this.ModelState);
}
}
So from then on to post a Student, you ignore the Teacher field and just post with TeacherId.
I haven't tested this with the OData client, but I can't think of why this wouldn't work. You will just have to use the Id field rather than the object.
Basically when you create the object
var associate = new Associate { /* ... */ };
It is not inserted into the database. It is created in the memory. When you call
context.SaveChanges();
It will be saved in the database. At this point database validation happens and key's are generated. Assuming your Id is unique identifier, that is generated in the datebase, note that in order for it to get updated value back from the database you need to have StoreGeneratedPattern set to Identity from Entity model view.
If this is not done your local context and database context no longer match. If you where to use that object with reference to something else it would fail.
I assume something like this would work:
Address address = new Address{ City = "Tallinn" /*etc*/};
context.SaveChanges();
//At this point Address will be in database context and has Id
associate = new Associate {
name = "Margus",
role = "Admin",
receiver = true,
representative = true,
AddressId = address.id
};
context.SaveChanges();
There is no solution to this. I will roll my own context with a notion of change sets that works with web-api. I will put it on github, when I'm done.
The only way addlink and setlink work is if the foreign key is nullable and you ahvbe to create a postput function call create link see here
I came across this and I can confirm that it is indeed a problem with the OData client (proxy), although I haven't found any references about it.
I managed to fix it using a workaround, which is not 100% perfect but works for me. Here is the code and I will explain about its shortcomings.
public static class DataServiceContextExtensions
{
public static int PostChanges(this DataServiceContext context)
{
using (var client = new WebClient())
{
client.Credentials = context.Credentials;
client.Headers[HttpRequestHeader.ContentType] = "application/json";
var entities = context.Entities.Where(x => x.State == EntityStates.Added);
foreach (var descriptor in entities)
{
var url = $"{context.BaseUri}{descriptor.Entity.GetType().Name}";
var data = JsonSerializer.Serialize(descriptor.Entity);
var response = client.UploadString(url, data);
context.ChangeState(descriptor.Entity, EntityStates.Detached);
}
return entities.Count();
}
}
}
As you can see, I am using an extension method over DataServiceContext where I iterate through all the entities stored in the change tracker which are marked as added, and then I use a WebClient to POST a JSON serialized version of them to the OData endpoint, using any credentials that the proxy might have.
Problems:
First, it only deals with added entities, I'm OK with that, but others may need a more comprehensive solution. The only way I see is to replace WebClient with some other client that can do arbitrary HTTP verbs.
Second, it doesn't hydrate the entities with the generated primary key. Again, I don't need it in my case, but this one will be difficult to solve, as OData does not seem to return it on the result of UploadString.
Third, all URLs are always, by convention, assumed to be composed as BaseUri + entity type (e.g., https://foo.bar/MyEntity). This may or may not always be the case, not 100% sure, again, works in my case.
I got one question related to my model you can see in the picture below.
As you can see I got 3 entities and 1:n and m:n relations between them.
I want that I can edit these models through a web interface. Therefore I scaffold (add controller with entity framework) these three models and got edit/delete/create/ views and of course one controller for each entity.
But there is no input/fields created for the relations automatically by VS. So I thought to implement them manually. Before I want to do that is there an simpler way to implement/scaffold this model, so I can even edit the relations(Checkboxes or (multi)select would be the best)?
Thanks in advance!
For one-many you can use a DropDownList for Tip in the Partner View (see Scott Allen's solution. Many-many can be handled by ViewModels and JavaScript frameworks like Knockout.
No, the scaffolds are intentionally unopinionated here, as there's many different ways you could handle this. Perhaps you just want to choose from a select list? Maybe you want checkboxes, instead? Or, maybe you want to actually add/edit related items inline? And with that last one, would you like to post all at once or use AJAX?
So, instead of picking for you, the framework rightly leaves the decision up to you, since only you know how your application should be built. Regardless, relying on the scaffolds is going to bite you more often than not. They only work in the most basic and ideal scenarios, and when have application requirements ever been either basic or ideal? I don't even bother with them at this point, preferring to just create my controllers/views manually. It ends up being quicker than dealing with the scaffold and undoing all the things that aren't applicable.
So, since you're looking for select boxes (either single-select or multi-select), first, I'd recommend creating view models for your entities. For example, with Tip:
public class TipViewModel
{
[Required]
public string Name { get; set; }
[Required]
[DataType(DataType.MultilineText)]
public string Description { get; set; }
[Required]
public int? SelectedPartnerId { get; set; }
public IEnumerable<SelectListItem> PartnerChoices { get; set;}
[Required]
public int? SelectedBookId { get; set; }
public IEnumerable<SelectListItem> BookChoices { get; set; }
}
Here, I've added nullable int (using a nullable allows them to be initially unselected, instead of just set to the first option) properties to track the id of the selected Book/Partner because it doesn't appear you have explicit properties on your entities for the foreign keys. That's fine, but it doesn't make it slightly more complicated to save the relationship, as you'll see in a bit. If you did have explicit foreign key properties, then you should mirror those in your view models instead.
Now in the GET version of your action, you'll need to do something like the following:
public ActionResult Create()
{
var model = new TipViewModel();
PopulateChoices(model);
return View(model);
}
...
protected void PopulateChoices(TipViewModel model)
{
model.PartnerChoices = db.Partners.Select(m => new SelectListItem
{
Value = m.Id.ToString(),
Text = m.Name
});
model.BookChoices = db.Books.Select(m => new SelectListItem
{
Value = m.Id.ToString(),
Text = string.Format("{0} by {1}", m.Name, m.Author)
});
}
I've abstracted out the code for populating these select lists because the code will be used multiple times throughout your controller. Also, I used string.Format on the Text value for the books just to show that you can do whatever you want with the text for the select list item. Also, the code above would be for a create action, obviously. Doing an edit would be similar but slightly different:
public ActionResult Edit(int id)
{
var tip = db.Tips.Find(id);
if (tip == null)
{
return new HttpNotFoundResult();
}
var model = new TipViewModel
{
Name = tip.Name,
Description = tip.Description,
SelectedPartnerId = tip.Partner != null ? tip.Partner.Id : new int?(),
SelectedBookId = tip.Book != null ? tip.Book.Id : new int?()
}
PopulateChoices(model);
return View(model);
}
The main difference is that you're obviously dealing with an existing instance so you need to pull it from the database. Then, you just need to map the data from your entity onto your view model. Since, again, you don't have explicit foreign key properties, you have to do a little extra leg work to get the currently chosen Partner/Book values, otherwise you could just copy the values for the foreign key properties over directly. Also, here, I'm just doing a manual mapping, but there's third-party libraries to make this task easier (see: AutoMapper).
With that, you can implement your views. Everything will work the same as it did when you were using the entity directly, you just need to make a couple of modifications. First, you'll need to change your view's model declaration:
#model Namespace.To.TipViewModel
Then, add the select lists for your two related properties:
#Html.DropDownListFor(m => m.SelectedPartnerId, Model.PartnerChoices)
...
#Html.DropDownListFor(m => m.SelectedBookId, Model.BookChoices)
The fun happens in the POST version of your actions. Most of the code will stay the same from the GET version, but now you'll have an if (ModelState.IsValid) block:
[HttpPost]
public ActionResult Create(TipViewModel model)
{
if (ModelState.IsValid)
{
// map the data from model to your entity
var tip = new Tip
{
Name = model.Name,
Description = model.Description,
Partner = db.Partners.Find(model.SelectedPartnerId),
Book = db.Books.Find(model.SelectedBookId)
}
db.Tips.Add(tip);
db.SaveChanges();
return RedirectToAction("Index");
}
// Form has errors, repopulate choices and redisplay form
PopulateChoices(model);
return View(model);
}
The edit version, again, is similar, except you're going to map onto you existing instance, for example:
tip.Name = model.Name;
tip.Description = model.Description;
tip.Partner = db.Partners.Find(model.SelectedPartnerId);
tip.Book = db.Books.Find(model.SelectedBookId);
That's all there is to it for reference properties. You don't actually have any thing that's M2M or even one-to-many on your entities in your question. Everything is one-to-one, but if you did have a collection property, you'd need to handle it slightly differently. You still need a property on your view model to hold the selected values and the available choices:
public List<int> SelectedFooIds { get; set; }
public IEnumerable<SelectListItem> FooChoices { get; set; }
Populating the choices would also be the same. The options are the options; it doesn't matter if you're select just one or many as far as that is concerned.
Mapping onto your entity in your create action would be different though, as you'd need to select all of the chosen items from the database and set your collection property on your entity to that:
var tip = new Tip
{
...
Foos = db.Foos.Where(m => model.SelectedFooIds.Contains(m.Id)),
}
And, you'd need to make changes to both the GET and POST versions of your edit action. For the GET, you need to condense your collection property down to a list of ids:
var model = new TipViewModel
{
...
SelectedFooIds = tip.Foos.Select(m => m.Id).ToList(),
}
And in the edit version, you set new selected items:
tip.Foos = db.Foos.Where(m => model.SelectedFooIds.Contains(m.Id);
Finally, in your views, you'd use ListBoxFor instead of DropDownListFor to enable the multiselect:
#Html.ListBoxFor(m => m.SelectedFooIds, Model.FooChoices)
I have been searching for a way to join 2 distantly related domain models into one view model with no luck.
I am working on an existing application and have been asked to add a field to a result of fax log search.
My controller is returning a viewModel, and I am just wanting to add an additional field to it. Which sounds like it should be an easy task.
Background Info:
This is the original viewModel:
public class VOEIFaxLogSearchListViewModel
{
public DateTime DateTimeAdded { get; set; }
public string Processor { get; set; }
public string FaxStatusCode { get; set; }
public string VendorOrderID { get; set; }
public string FromFaxNumber { get; set; }
}
I want to add an additional field to this viewmodel:
public string CustomerName { get; set; }
The way that the application is designed, a stored procedure is called to return a dataset of the search results. (I won't the search method (GetFaxLogSearchResult) or its SQL call as it isn't necessary)
var resultFaxDS = vOEIDAO.GetFaxLogSearchResult(startDate,endDate,userName,faxType);
The resulting DataSet is then converted to a DataTable.
DataTable faxTable = resultFaxDS.Tables[0];
A For loop interates through each of the result records and puts them into a Domain Model named FaxModel. Which is mapped with Automapper to the viewModel named FaxLogSearchListViewModel.
for (int i=0; i<faxTable.Rows.Count;i++)
{
var row = faxTable.Rows[i];
var faxLogModel = vOEIDAO.DRToFaxModel(row);
faxViewModel.Add(Mapper.Map<FaxModel,FaxLogSearchListViewModel>(faxLogModel));
}
}
return faxViewModel;
}
Here is what I have done so far to add this result field:
1) added the new property to the view model.
2) modified stored procedure that pulls back the search results so it returns CustomerName in the dataset
The dilemna:
The method adding each row of the dataset into the Domain model (DRToFaxModel) is doing just that... it is populating a domain model(FaxModel). The field that I want to add isn't in the Domain model.
As a result, I don't want to add a field to the domain model if it doesn't belong to the concrete class.
Here is the domain model and the method used to populate it with each row from the search results:
public class FaxModel
{
public int FaxID { get; set; }
public int FaxStatusID { get; set; }
public string ToFaxNumber { get; set; }
public string FromFaxNumber { get; set; }
public DateTime DateTimeAdded { get; set; }
public string FaxStatusCode { get; set; }
public string Processor { get; set; }
public string VendorOrderID { get; set; }
}
public FaxModel DRToFaxModel(DataRow dr)
{
FaxModel voObj = new FaxModel();
voObj.FaxID = GetVOInt(dr["FaxID"]);
voObj.FaxStatusID = GetVOSmallInt(dr["FaxStatusID"]);
voObj.ToFaxNumber = GetVOStr(dr["ToFaxNumber"]);
voObj.FromFaxNumber = GetVOStr(dr["FromFaxNumber"]);
voObj.DateTimeAdded = GetVODateTime(dr["DateTimeAdded"]);
voObj.FaxStatusCode = GetVOStr(dr["FaxStatusCode"]);
voObj.Processor = GetVOStr(dr["Processor"]);
voObj.VendorOrderID = GetVOStr(dr["VendorOrderID"]);
//Cant add CustomerName to the model without modifying the FaxModel domain model.
//Shouldn't do that because it is a domain model.
//CustomerName is in the CustomerModel domain Model
// voObj.CustomerName = GetVOStr(dr["CustomerName"]);
return voObj;
}
So currently, my ViewModel with the added CustomerName property is returned with a null for CustomerName.
My domain models are distantly related.
In the database the FAX table can be joined joined to the CUSTOMER table but only by joining through an ORDER table. (the FAX table has an orderID field and the ORDER table has a CustomerID field)
So my resulting question is:
how do you use autoMapper to map a Fax domain model to a Customer domain model since the 2 domains don't have any common fields to build the relationship without joining through another table?
Or can you map more than 2 tables into 1 viewModel using automapper? how is this done?
What a great question. First of all, it's so refreshing to see someone asking about the proper way to do something, rather that just seeking a quick fix. Second, the amount of documentation provided is exactly the way SO questions should be written. I wish I could give this more than +1.
That said, since you're essentially asking an architecture question, there aren't any concrete answers, just opinions.
Here's my opinion:
You state the result of the sproc is mapped to a domain model:
var resultFaxDS = vOEIDAO.GetFaxLogSearchResult(startDate,endDate,userName,faxType);
However, you've added a return field, CustomerName to your sproc which is not part of the domain model. I think that's the heart of your issue.
There's a choice to be made here: does this sproc return a domain model or doesn't it?
Right now, my opinion is that it does not represent a domain model anymore, due to the new field, so you should not be trying to map it to a domain model before mapping it to your view model. You need to create a new data type to map this result to, which represents what you are actually getting from the sproc, and map that to your view model.
The alternate option is that this sproc does in fact represent a domain model. If that is the case, you should not be adding a new field to it that is not part of the model. Rather, you'll need to get the FaxModel domain objects and CustomerModel domain objects separately, and assemble your view models from both objects.
This is an example of the Single Responsibility Principle, meaning that an object, function, assembly, heck, even a program, should have one purpose. By giving your sproc a return value that both is and isn't a domain model, you're giving it more than one purpose. It would be best to either decide that it represents a FaxModel, and accept that the customer name needs to come from another source, or decide that it returns something else, say CustomerFaxModel which contains both customer and fax information, and use it as such.
To answer your technical question, AutoMapper does allow you to pass an existing target object to the map function in addition to a source object. You can map the target from object A to get some fields, and then pass the already mapped target to Map() a second time with a source of object B to map other fields.
Always, always, keep asking questions like this and you'll do well.
I have an Entity in EF called Advertiser and another called Client. Advertisers have a association field called Client, which is selected from a dropdownlist. I want to know how to save this association to the database. The approach I've used is to find the Client object (by using the Id) and then assign this Client object to the Advertiser.Client navigation property. I hoped that by then Adding this Advertiser property, I'd have added an Advertiser that is associated with an existing Entity. However this was not the result. Instead, a new Client record also got added to the table. How do I fix this?
Full explanation and code bits are below...
public class Advertiser
{
public int Id { get; set; }
public string Name { get; set; }
//Navigation Properties
public virtual Client Client { get; set; }
}
And another called Client
public class Client
{
public Client()
{
Advertisers = new List<Advertiser>();
}
public int Id { get; set; }
public string Name { get; set; }
// Navigation Properties
public virtual ICollection<Advertiser> Advertisers { get; set; }
}
A bunch of clients are added to the database in a separate view. When the user lands on the Advertiser views, they have the create option. What I want the create to do is allow the user to pick a client from a drop down list containing all clients. I want this advertiser to then be associated with that client.
This is the code for the controller:
//
// POST: /Advertiser/Create
[HttpPost]
public ActionResult Create(Advertiser advertiser,int Id)
{
if (ModelState.IsValid)
{
advertiser.Client = clientRepo.Retrieve(Id); // Finds and returns a Client object
System.Diagnostics.Debug.WriteLine("Saving Advertiser, with int Id = {0} and Client.Id = {1}", Id, advertiser.Client.Id);
repo.Create(advertiser);
repo.SaveChanges();
return RedirectToAction("Index");
}
return View(advertiser);
}
The Advertiser view populates a dropdownlist with all the Clients and then returns the Id for the currently selected Client.
<div class="editor-field">
#{
var clients = new Repository<Client>().FetchAll();
var clientLists = new SelectList(clients, "Id", "Name");
}
#Html.DropDownList("Id", clientLists)
</div>
Now, this view correctly returns the correct Id. The Debug.Writeline also confirms that the correct Id is being passed back. The problem lies in what happens after that...
Instead of inserting a new Advertiser that is associated with the existing Client entity, what it does is, it first inserts an Advertiser, and then inserts a copy of the Client entity to the database. This results in duplicate Clients that differ only in primary key (Id),
I know this can be solved by exposing the foreign key and passing the foreign key instead of finding and referencing the appropriate Client to the the Advertiser.Client property. But if possible I'd prefer to do this without exposing foreign keys. Is there some way this can be done? ... i.e. What am I doing wrong?
If what goes on in the Repository class could be useful to answer this question, I've added it below:
public OperationStatus Create(TEntity item)
{
OperationStatus status = new OperationStatus {Status = true};
var value = DataContext.Set<TEntity>().Add(item);
if(value == null)
{
status = null;
}
return status;
}
public TEntity Retrieve(int id)
{
return DataContext.Set<TEntity>().Find(id);
}
Add a [Key] Attribute to the ID property on both Client and Advertiser