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Adding a value in two different tables in my create controller [duplicate]

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How to save the record mutipule table using Asp.net MVC Json
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I have a Create controller that creates a record in one table [Kursus_kursist] using db.Add, dbSaveChanges().
I need to create a record in another table [jobcoach] based on one of the values (kursus_kursist_id which is an int), but I don't know how to pass the value.
public ActionResult Create([Bind(Include = "kursus_kursist_id,kursist_id,status, jc")] kursus_kursist kursus_kursist)
{
if (ModelState.IsValid)
{
db.kursus_kursist.Add(kursus_kursist);
db.SaveChanges();
db.jobcoach.Add(/*I THINK THE KURSUS_KURSIST_ID NEEDS TO GO HERE*/);
db.SaveChanges();
return RedirectToAction("../kursister/Index");
}
I've been able to create a record in both the usus_kursist and jobcoach tables, but in the jobcoach table I don't get the kursus_kursist_id - so basically an empty record (aside from the PK).

When you add to the database and save, that entity becomes tracked. The tracked entity have an assigned Id.
var myEntity = new SomeEntity(){
Name="Test",
CreatedDate = DateTime.UtcNow
}
dbContext.MyEntities.Add(myEntity);
dbContext.SaveChanges();
Console.WriteLine(myEntity.Id);
This will give you the proper Id EF assigned your entity.
If JobCoach is connected you could also add them in their existing relation.
var myEntity = new SomeEntity(){
Name="Test",
CreatedDate = DateTime.UtcNow,
MyChildObject = new ChildObject(){
Name="Something else",
CreatedDate = DateTime.UtcNow
}
dbContext.MyEntities.Add(myEntity);
dbContext.SaveChanges();
Console.WriteLine(myEntity.MyChildObject.Id);
So in your case you should be able to use your first kursist_thingie.Id after you saved that entity. Assign JobCoach.KursistId = kursist_thingie.Id or however you please.
Hope it helps!

How to update many to many in Entity Framework with AutoDetectChangesEnabled = false

Please, help me to handle this situation:
I meaningly switched off AutoDetectChangesEnabled and I load my
entities AsNoTracked() meaningly either.
And I can't update many-to-many relationship in this case:
Here is the code of Update method:
public void Update(User user)
{
var userRoleIds = user.Roles.Select(x => x.Id);
var updated = _users.Find(user.Id);
if (updated == null)
{
throw new InvalidOperationException("Can't update user that doesn't exists in database");
}
updated.Name = user.Name;
updated.LastName = user.LastName;
updated.Login = user.Login;
updated.Password = user.Password;
updated.State = user.State;
var newRoles = _roles.Where(r => userRoleIds.Contains(r.Id)).ToList();
updated.Roles.Clear();
foreach (var newRole in newRoles)
{
updated.Roles.Add(newRole);
}
_context.Entry(updated).State = EntityState.Modified;
}
All simple fields, like Name, LastName updated. But the set
of Roles for User doesn't get updated - it stays the same.
I tried loading Roles using
_context.Entry(updated).Collection("Roles").Load();
But I can't update this loaded set in any way.
I searched for similar items but failed to find the answer, thought it definitely already exists.
I'm really sorry for possible dublicate.
PS. I want to add that I don't want to delete or update child entities at all.
A lot of existing answers suggest manually delete / add child entities to database in whole, but it is not suitable for me.
Roles are independent entities, any other user can use them.
I just want to update User_Role table in database, but I can't.

How can I ensure that Entity Framework will create an association in a many-to-many relationship instead of a new record?

I have a problem with Entity Framework.... I don't know it well.
I am working on a seemingly simple task of associating an existing contact to a new order in a system I'm working on. Contacts will always exist prior to being associated to the order.
Simplified database tables...
Order
OrderID
Status
Created
Contact
ContactID
FirstName
LastName
ContactToOrderMap
OrderID
ContactID
I've linked these two tables in the DbContext.
modelBuilder.Entity<Order>()
.HasMany<Contact>(a => a.Contacts)
.WithMany()
.Map(a =>
{
a.ToTable("ContactToOrderMap");
a.MapLeftKey("OrderID");
a.MapRightKey("ContactID");
});
I wrote a unit test that simply creates an order, a contact, adds the contact to a list member on the order and attempts to save.
// setup
var order = new Order() { // initialize required fields };
// add a contact that already exists in the database
var orderContact = new Contact() { ID = 2 };
order.Contacts.Add(orderContact);
// call
logic.Save(ref order);
Eventually this order is saved after some unrelated business logic is performed...
// Add to collection
_db.Orders.Add(obj);
// Commit changes
_db.SaveChanges();
>> Here I receive errors related to required database fields on the Contact table. Not what I'm looking for as I really just want to add an association record in the ContactToOrderMap table.
As a next step, I tried to retrieve the existing contacts from the database prior to saving the order. This code's not super clean, but it should explain what I'm attempting.
if (currentOrder.Contacts != null)
{
var matchedContacts = new List<Contact>();
foreach (var con in currentOrder.Contacts)
{
matchedContacts.Add(_contactLogic.Get(con.ID));
}
currentOrder.Contacts.Clear();
foreach (var item in matchedContacts)
{
currentOrder.Contacts.Add(item);
}
}
This created the association, but created a new Contact (new unique ID) as well.
The goal is to create an association and a new order only, not create a new contact.
Any ideas or pointers to get me going in the right direction?
Please let me know if additional information is required.
Edit: Fixed code - renamed obj to currentOrder.

After the line
var orderContact = new Contact() { ID = 2 };
do
_db.Contacts.Attach(orderContact);
Now the contact is part of the context in an Unchanged state, and
order.Contacts.Add(orderContact);
will not change its state to Added anymore.

dbset.local updating database: a duplicate value cannot be inserted into a unique index

I am getting an error when calling entities.savechanges() on my EF 4.3.1. My database is a sql ce v4 store and I am coding in the mvvm pattern. I have a local version of my context that I send to an observable collection and modify etc. This works fine, and when I call savechanges() when no rows exist in the database the objects persist fine. When I reload the application, the objects are populated in my listbox as they should, however if I add another object and call savechanges() I get an error saying that a duplicate value cannot be inserted into a unique index.
From my understanding it means that the context is trying to save my entities to the datastore, but it seems to be adding my untouched original objects as well as the new one. I thought it would leave them alone, since their state is unchanged.
private void Load()
{
entities.Properties.Include("Images").Load();
PropertyList = new ObservableCollection<Property>();
PropertyList = entities.Properties.Local;
//Sort the list (based on previous session stored in database)
var sortList = PropertyList.OrderBy(x => x.Sort).ToList();
PropertyList.Clear();
sortList.ForEach(PropertyList.Add);
propertyView = CollectionViewSource.GetDefaultView(PropertyList);
if (propertyView != null) propertyView.CurrentChanged += new System.EventHandler(propertyView_CurrentChanged);
private void NewProperty()
{
try
{
if (PropertyList != null)
{
Property p = new Property()
{
ID = Guid.NewGuid(),
AgentName = "Firstname Lastname",
Address = "00 Blank Street",
AuctioneerName = "Firstname Lastname",
SaleTitle = "Insert a sales title",
Price = 0,
NextBid = 0,
CurrentImage = null,
Status = "Auction Pending",
QuadVis = false,
StatVis = false, //Pause button visibility
Sort = PropertyList.Count + 1,
};
PropertyList.Add(p);
SaveProperties();
}
private void SaveProperties()
{
try
{
foreach (var image in entities.Images.Local.ToList())
{
if (image.Property == null)
entities.Images.Remove(image);
}
}
catch (Exception ex)
{
System.Windows.MessageBox.Show(ex.Message);
}
entities.SaveChanges();
}

Without commenting on all the code here this is the bit that's causing the specific problem you bring up:
//Sort the list (based on previous session stored in database)
var sortList = PropertyList.OrderBy(x => x.Sort).ToList();
PropertyList.Clear();
sortList.ForEach(PropertyList.Add);
This code:
Starts with entities that have been queried and are being tracked by the context as Unchanged entities. That is, entities that are known to already exist in the database.
Creates a new sorted list of these entities.
Calls Clear on the local collection causing each tracked entity to be marked as deleted and removed from the collection.
Adds each entity back to the context putting it now in an Added state meaning that it is new and will be saved to the database when SaveChanges is called,
So effectively you have told EF that all the entities that exist in the database actually don't exist and need to be saved. So it tries to do this and it results in the exception you see.
To fix this don't clear the DbContext local collection and add entities back. Instead you should sort in the view using the local collection to back the view.

It sounds like you're adding the existing entities to the context (which marks them for insertion) instead of attaching them (which marks them as existing, unmodified).
I'm also not sure that new Guid() isn't returning the same guid... I always use Guid.NewGuid() http://msdn.microsoft.com/en-us/library/system.guid.newguid.aspx

LINQ to SQL Insert Multiple Tables Question

I have 3 tables. A primary EmploymentPlan table with PK GUID EmploymentPlanID and 2 FK's GUID PrevocServicesID & GUID JobDevelopmentServicesID. There are of course other fields, almost exclusively varchar(). Then the 2 secondary tables with the corresponding PK to the primary's FK's.
I am trying to write the LINQ INSERT Method and am struggling with the creation of the keys. Say I have a method like below. Is that correct? Will that even work? Should I have seperate methods for each?
Also, when inserting I didn't think I needed to provide the PK for a table. It is auto-generated, no?
Thanks.
public static void InsertEmploymentPlan(int planID, Guid employmentQuestionnaireID, string user, bool communityJob, bool jobDevelopmentServices, bool prevocServices, bool transitionedPrevocIntegrated, bool empServiceMatchPref)
{
using (var context = MatrixDataContext.Create())
{
var empPrevocID = Guid.NewGuid();
var prevocPlan = new tblEmploymentPrevocService
{
EmploymentPrevocID = empPrevocID
};
context.tblEmploymentPrevocServices.InsertOnSubmit(prevocPlan);
var empJobDevID = Guid.NewGuid();
var jobDevPlan = new tblEmploymentJobDevelopmetService()
{
JobDevelopmentServicesID = empJobDevID
};
context.tblEmploymentJobDevelopmetServices.InsertOnSubmit(jobDevPlan);
var empPlan = new tblEmploymentQuestionnaire
{
CommunityJob = communityJob,
EmploymentQuestionnaireID = Guid.NewGuid(),
InsertDate = DateTime.Now,
InsertUser = user,
JobDevelopmentServices = jobDevelopmentServices,
JobDevelopmentServicesID =empJobDevID,
PrevocServices = prevocServices,
PrevocServicesID =empPrevocID,
TransitionedPrevocToIntegrated =transitionedPrevocIntegrated,
EmploymentServiceMatchPref = empServiceMatchPref
};
context.tblEmploymentQuestionnaires.InsertOnSubmit(empPlan);
context.SubmitChanges();
}
}
I understand I can use more then 1 InsertOnSubmit(), See this question, I just don't understand how that would apply to my situation and the PK/FK creation.

The pk can be auto generated when the table's definition in the db does it for you. Also the property for the corresponding pk on the linq model has to configured to be updated after the insert, so it gets the auto generated ID.
I don't think the relation on those tables is on your linq model. Otherwise you should be able to do:
using (var context = MatrixDataContext.Create())
{
var empPlan = new tblEmploymentQuestionnaire
{
CommunityJob = communityJob,
InsertDate = DateTime.Now,
InsertUser = user,
JobDevelopmentServices = jobDevelopmentServices,
JobDevelopmentService = new tblEmploymentJobDevelopmetService(),
PrevocServices = prevocServices,
PrevocService = new tblEmploymentPrevocService(),
PrevocServicesID =empPrevocID,
TransitionedPrevocToIntegrated =transitionedPrevocIntegrated,
EmploymentServiceMatchPref = empServiceMatchPref
};
context.tblEmploymentQuestionnaires.InsertOnSubmit(empPlan);
context.SubmitChanges();
}
ps. not having the relation in the model is a design decision, so the above doesn't mean that's the only way to do it. The way you showed (with the extra SubmitChanges calls as in the other answer) is perfectly valid, just responds to a different design.

I think the issue is (if I understand it correctly) you are deferring the inserting, except you don't know it...
Since you're creating FKs but differing their insertion until the end, it doesn't know what to do, so when you try to create the main entry it's enforcing the FK constraints (which might not exist yet), thus failing. Try creating the FK entries and actually submitting the changes to the database before insert the main entry.
For example, say you have the following tables:
Child
Toy
ToyOwner
ToyOwner has FK constraints on Child and Toy. If the entries are missing in that table, you will not be able to insert an entry into ToyOwner. So you'd have to do something like the following:
Child myChild;
Toy myToy;
//Queue up the changes that are going to be submitted
InsertOnSubmit(myChild)
InsertOnSubmit(myToy)
//Submit the queue
SubmitChanges();
//Now that those FKs are filled, we can insert the main entry with those FK values
ToyOwner = new myToyOwner
myToyOwner.Child = myChild
myToyOwner.Toy = myToy
//And insert the new queue into the DB
InsertOnSubmit(myToyOwner)
SubmitChanges();