How can I retrieve Id of inserted entity using Entity framework

Question

I have a problem with Entity Framework in ASP NET  I want to get the Id value whenever I add an object to database  How can I do this  According to Entity Framework the solution is  using  var context   new EntityContext          var customer   new Customer                 Name    quot John quot              context Customers Add customer       context SaveChanges                 int id   customer CustomerID     This doesn t get the database table identity  but gets the assigned ID of the entity  if we delete a record from the table the seed identity will not match the entity ID

User · Answer

You need to reload the entity after saving changes. Because it has been altered by a database trigger which cannot be tracked by EF. SO we need to reload the entity again from the DB,

db.Entry(MyNewObject).GetDatabaseValues();

Then

int id = myNewObject.Id;

Look at @jayantha answer in below question:

How can I get Id of the inserted entity in Entity framework when using defaultValue?

Looking @christian answer in below question may help too:

Entity Framework Refresh context?

User · Answer

I come across a situation where i need to insert the data in the database  amp  simultaneously require the primary id using entity framework  Solution    long id  IGenericQueryRepository lt myentityclass  Entityname gt  InfoBase   null  try        InfoBase   new GenericQueryRepository lt myentityclass  Entityname gt         InfoBase Add generalinfo       InfoBase Context SaveChanges        id   entityclassobj ID      return id

User · Answer

Repository addorupdate entity  entity id   Repository savechanges    Var id   entity id    This will work

User · Answer

I had been using Ladislav Mrnka s answer to successfully retrieve Ids when using the Entity Framework however I am posting here because I had been miss-using it  i e  using it where it wasn t required  and thought I would post my findings here in-case people are looking to  quot solve quot  the problem I had  Consider an Order object that has foreign key relationship with Customer  When I added a new customer and a new order at the same time I was doing something like this  var customer   new Customer      no Id yet  var order   new Order      requires Customer Id to link it to customer  context Customers Add customer   context SaveChanges     this generates the Id for customer order CustomerId   customer Id   finally I can set the Id  However in my case this was not required because I had a foreign key relationship between customer Id and order CustomerId All I had to do was this  var customer   new Customer      no Id yet  var order   new Order Customer   customer    context Orders Add order   context SaveChanges     adds customer Id to customer and the correct CustomerId to order  Now when I save the changes the id that is generated for customer is also added to order  I ve no need for the additional steps I m aware this doesn t answer the original question but thought it might help developers who are new to EF from over-using the top-voted answer for something that may not be required  This also means that updates complete in a single transaction  potentially avoiding orphin data  either all updates complete  or none do

User · Answer

There are two strategies     Use Database-generated ID  int or GUID   Cons   You should perform SaveChanges   to get the ID for just saved entities   Pros   Can use int identity  Use client generated ID - GUID only   Pros  Minification of SaveChanges operations  Able to insert a big graph of new objects per one operation   Cons   Allowed only for GUID

User · Answer

When you use EF 6 x code first       DatabaseGenerated DatabaseGeneratedOption Identity       public Guid Id   get  set      and initialize a database table  it will put a    newsequentialid      inside the table properties under the header Default Value or Binding  allowing the ID to be populated as it is inserted   The problem is if you create a table and add the    DatabaseGenerated DatabaseGeneratedOption Identity     part later  future update-databases won t add back the  newsequentialid     To fix the proper way is to wipe migration  delete database and re-migrate    or you can just add  newsequentialid    into the table designer

User · Answer

You can get ID only after saving  instead you can create a new Guid and assign before saving

User · Answer

The object you re saving should have a correct Id after propagating changes into database

User · Answer

All answers are very well suited for their own scenarios  what i did different is that i  assigned the int PK directly from object  TEntity  that Add   returned to an int variable like this   using  Entities entities   new Entities            int employeeId   entities Employee Add new Employee                                                       EmployeeName   employeeComplexModel EmployeeName                              EmployeeCreatedDate   DateTime Now                              EmployeeUpdatedDate   DateTime Now                              EmployeeStatus   true                            EmployeeId              use id for other work     so instead of creating an entire new object  you just take what you want     EDIT For Mr   GertArnold

User · Answer

It is pretty easy  If you are using DB generated Ids  like IDENTITY in MS SQL  you just need to add entity to ObjectSet and SaveChanges on related ObjectContext  Id will be automatically filled for you   using  var context   new MyContext        context MyEntities Add myNewObject     context SaveChanges       int id   myNewObject Id     Yes it s here     Entity framework by default follows each INSERT with SELECT SCOPE IDENTITY   when auto-generated Ids are used

User · Answer

You have to set the property of StoreGeneratedPattern to identity and then try your own code  Or else you can also use this  using  var context   new MyContext        context MyEntities AddObject myNewObject     context SaveChanges       int id   myNewObject Id     Your Identity column ID

[c#] How can I retrieve Id of inserted entity using Entity framework?

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