I'm having trouble retrieving the ID of newly added object in EF Core using the UoW pattern. I have this service:
public class OrderService : IOrderService
{
private IUnitOfWork _uow;
private IOrderRepository _orderRepository;
private IPaymentRepository _paymentRepository;
public OrderService(IUnitOfWork uow,
IOrderRepository orderRepository,
IPaymentRepository paymentRepository)
{
_uow = uow;
_orderRepository = orderRepository;
_paymentRepository = paymentRepository;
}
public int CreateOrder(Logic.Order order)
{
var id = _orderRepository.CreateOrder(order);
var payment = new Data.Payment();
payment.OrderId = id; // at this point, this is -2147353458 something
_paymentRepository.CreatePayment(payment);
// committed at this point but I can't get id unless I re-query
_uow.Commit();
// this is still -2147353458
return id;
}
}
So CreateOrder just adds a new order and then the newly generated ID is returned and used by the Payment object in CreatePayment. The problem with this since after adding, it is not committed yet so EF Core generates a temp id (something like -2147483324) so this is what I get. I then pass this to payment but this part is ok since I think EF is tracking it. The problem is what I return to the UI.
The service is called by the UI and after comitting, I can't get the ID. That's been my problem for hours now.
I've recently came across the same problem as well. Am here just to share my solution for reference.
Rather than to committing the transaction for the Id, you could try utilizing EF relationships.
Ex: the payment and order Model
public class Order
{
public int Id{ get; set; }
public Payment Payment { get; set; }
}
public class Payment
{
public int Id{ get; set; }
public int OrderId{ get; set; }
[ForeignKey("OrderId")]
public Order Order { get; set; }
}
Then in your transaction, you could simply assign the order to payment, EF will automatically insert the created Order Id to payment upon committing the transaction :
public int CreateOrder(Logic.Order order)
{
_orderRepository.CreateOrder(order);
var payment = new Data.Payment();
payment.Order = order;
_paymentRepository.CreatePayment(payment);
_uow.Commit();
return order.id;
}
You need to create an abstract method just like that "void Commit(EntityBase entity)" in your Uow, inside the method call your saveChanges this way you ensure that memory address is the same, so outside of the method you are able to access the property Id, be careful if you're using some Mapper because this may change you Memory Address. Make sure that your are using mapper only after Call UoW.Commit!
public class EntityBase
{
public int Id {get;set}
}
public class AnyOtherEntity : EntityBase
{
}
public void Commit(EntityBase entity)
{
yourContext.SaveChanges(entity);
}
Uow.Commit(AnyOtherEntity);
AnyOtherEntity.Id;
There is no option except commiting the transaction if you want to retrieve the generated unique Id immediately. Also,
// this is still -2147353458
return id;
You can't expect to be changed primitive type after commit. You should get it by order.Id, because after the transaction committed the EF will update entity because EF is tracking the entity.
public int CreateOrder(Logic.Order order)
{
_orderRepository.CreateOrder(order);
// commit the transaction
_uow.Commit();
var payment = new Data.Payment();
// Get the id of inserted row
payment.OrderId = order.Id;
_paymentRepository.CreatePayment(payment);
_uow.Commit();
return order.Id;
}
I have two classes, here are the relevant bits:
public class Endorsement
{
public Guid? ContractId { get; set; }
public virtual Contract Contract { get; set; }
}
public class Contract
{
public virtual ICollection<Endorsement> Sales { get; set; }
}
The Endorsement class doesn't have a corresponding configuration, but the Contract class does:
public class ContractConfiguration : EntityTypeConfiguration<Contract>
{
public ContractConfiguration()
{
HasMany(a => a.Sales).WithRequired(a => a.Contract).HasForeignKey(a => a.ContractId);
}
}
I'm trying to change the Contract on an Endorsement to another Contract:
var endorsement = Context.Set<Endorsement>().Find(endorsementId);
var newContract = Context.Set<Contract>().Find(newContractId);
endorsement.Contract = newContract;
/* Instead of the line above, I have also tried endorsement.ContractId = newContract.Id;
I have also tried newContract.Sales.Add(endorsement); and then setting the state of
the newContract entry to modified and saving, all with the same results.
*/
var entry = Context.Entry(endorsement);
entry.State = EntityState.Modified;
Context.SaveChanges();
Context.SaveChanges(); throws the following exception:
The changes to the database were committed successfully, but an error occurred while updating the object context. The ObjectContext might be in an inconsistent state. Inner exception message: A referential integrity constraint violation occurred: The property value(s) of 'Contract.Id' on one end of a relationship do not match the property value(s) of 'Endorsement.ContractId' on the other end.
Any idea what's causing this?
I already have a database with tables outside EF scope. But I want that the tables which will be used by EF to be created automatically.
public class SessionInfo
{
public Guid Id {get;set;}
public string Name { get; set; }
public DateTime StartsOn { get; set; }
public DateTime EndsOn { get; set; }
public string Notes { get; set; }
}
public class StudentsDbContext:DbContext
{
public StudentsDbContext():base("name=memory")
{
Database.Log = s => this.LogDebug(s);
}
public DbSet<SessionInfo> Sessions { get; set; }
}
This code just throws an exception because the table SessionInfoes doesn't exist.
using (var db = new StudentsDbContext())
{
db.Sessions.Add(new SessionInfo() {Id = Guid.NewGuid(), Name = "bla"});
var st = db.Sessions.FirstOrDefault();
}
What do I need to do so that EF will create the "SessionInfoes" (whatever name, it's not important) table by itself? I was under the impression that Ef will create the tables when the context is first used for a change or a query.
Update
After some digging, it seems that EF and Sqlite don't play very nice together i.e at most you can use EF to do queries but that's it. No table creation, no adding entities.
EF needs additional information in order to do this. You'll have to specify an IDatabaseInitializer first. Take a look at this list and find one that is appropriate for your needs (for example: MigrateDatabaseToLatestVersion, DropCreateDatabaseAlways, DropCreateDatabaseIfModelChanges, etc).
Then create your class:
public class MyDatabaseInitializer : MigrateDatabaseToLatestVersion
<MyDbContext,
MyDatabaseMigrationConfiguration>
Then also create the configuration for the initializer (ugh right?):
public class DatabaseMigrationsConfiguration
: DbMigrationsConfiguration<MyDbContext>
{
public DatabaseMigrationsConfiguration()
{
this.AutomaticMigrationDataLossAllowed = true;
this.AutomaticMigrationsEnabled = true;
}
protected override void Seed(MyDbContext context)
{
// Need data automagically added/update to the DB
// during initialization?
base.Seed(context);
}
}
Then one way to initialize the database is:
var myContext = new MyDbContext(/*connectionString*/);
Database.SetInitializer<MyDbContext>(new MyDatabaseInitializer());
myContext.Database.Initialize(true);
Some people prefer the to use the command line to migrate databases, but I don't want to assume I'll always have access to the database from a command lin.
Edit Is this post lacking sufficient information to get some guidance?
I have this method to insert an entity into the database:
public void Insert(T entity)
{
_context.Set<T>().Add(entity);
_context.SaveChanges();
}
When I inspect entity before adding it to the context, my CustomerRole field is there. Once the add has taken place, the context doesn't seem to have it. Because of this, I am receiving this error:
Entities in 'CcDataContext.Customers' participate in the
'Customer_CustomerRole' relationship. 0 related
'Customer_CustomerRole_Target' were found. 1
'Customer_CustomerRole_Target' is expected.
These images show what I mean:
Inspecting my entity
Inspecting the context
Can anyone explain this behaviour and what I can do about it?
This is the structure of my classes (cut down for brevity):
public class Customer : BaseEntity
{
public CustomerRole CustomerRole { get; set; }
}
class CustomerMap : EntityTypeConfiguration<Customer>
{
public CustomerMap()
{
HasRequired(t => t.CustomerRole)
.WithMany(t => t.Customers);
}
}
public class CustomerRole : BaseEntity
{
private ICollection<Customer> _customers;
public ICollection<Customer> Customers
{
get { return _customers ?? (new List<Customer>()); }
set { _customers = value; }
}
}
I can confirm that customer map is being added to the configuration and my database is built in line with them.
This is the call I am making which does the insert:
public Customer InsertGuestCustomer()
{
var customer = new Customer();
CustomerRole guestRole = GetCustomerRoleByName("Guest");
if (guestRole == null)
throw new Exception("Customer Role is not defined!");
customer.UserName = "";
customer.EmailAddress = "";
customer.Password = "";
customer.IsAdmin = false;
customer.CustomerRole = guestRole;
_customerRepository.Insert(customer);
return customer;
}
I have no other data in my database, this would be the first customer record and only one CustomerRole. My Customer table has a Foreign Key pointing to my CustomerRole.Id table / column.
Mark your navigation properties as virtual and initialize the collection property in the entity constructor rather than from the property getter.
public class Customer : BaseEntity
{
public virtual CustomerRole CustomerRole { get; set; }
}
...
public class CustomerRole : BaseEntity
{
public CustomerRole()
{
Customers = new List<Customer>();
}
public virtual ICollection<Customer> Customers { get; protected set; }
}
In your Customers property, you were returning a new List in the getter when the backing field was null, but you never assigned this to your backing field.
I have a table in my database called SEntries (see below the CREATE TABLE statement). It has a primary key, a couple of foreign keys and nothing special about it. I have many tables in my database similar to that one, but for some reason, this table ended up with a "Discriminator" column on the EF Proxy Class.
This is how the class is declared in C#:
public class SEntry
{
public long SEntryId { get; set; }
public long OriginatorId { get; set; }
public DateTime DatePosted { get; set; }
public string Message { get; set; }
public byte DataEntrySource { get; set; }
public string SourceLink { get; set; }
public int SourceAppId { get; set; }
public int? LocationId { get; set; }
public long? ActivityId { get; set; }
public short OriginatorObjectTypeId { get; set; }
}
public class EMData : DbContext
{
public DbSet<SEntry> SEntries { get; set; }
...
}
When I try to add a new row to that table, I get the error:
System.Data.SqlClient.SqlException: Invalid column name 'Discriminator'.
This problem only occurs if you are inheriting your C# class from another class, but SEntry is not inheriting from anything (as you can see above).
In addition to that, once I get the tool-tip on the debugger when I mouse over the EMData instance for the SEntries property, it displays:
base {System.Data.Entity.Infrastructure.DbQuery<EM.SEntry>} = {SELECT
[Extent1].[Discriminator] AS [Discriminator],
[Extent1].[SEntryId] AS [SEntryId],
[Extent1].[OriginatorId] AS [OriginatorId],
[Extent1].[DatePosted] AS [DatePosted],
[Extent1].[Message] AS [Message],
[Extent1].[DataEntrySource] AS [DataE...
Any suggestions or ideas where to get to the bottom of this issue? I tried renaming the table, the primary key and a few other things, but nothing works.
SQL-Table:
CREATE TABLE [dbo].[SEntries](
[SEntryId] [bigint] IDENTITY(1125899906842624,1) NOT NULL,
[OriginatorId] [bigint] NOT NULL,
[DatePosted] [datetime] NOT NULL,
[Message] [nvarchar](500) NOT NULL,
[DataEntrySource] [tinyint] NOT NULL,
[SourceLink] [nvarchar](100) NULL,
[SourceAppId] [int] NOT NULL,
[LocationId] [int] NULL,
[ActivityId] [bigint] NULL,
[OriginatorObjectTypeId] [smallint] NOT NULL,
CONSTRAINT [PK_SEntries] PRIMARY KEY CLUSTERED
(
[SEntryId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[SEntries] WITH CHECK ADD CONSTRAINT [FK_SEntries_ObjectTypes] FOREIGN KEY([OriginatorObjectTypeId])
REFERENCES [dbo].[ObjectTypes] ([ObjectTypeId])
GO
ALTER TABLE [dbo].[SEntries] CHECK CONSTRAINT [FK_SEntries_ObjectTypes]
GO
ALTER TABLE [dbo].[SEntries] WITH CHECK ADD CONSTRAINT [FK_SEntries_SourceApps] FOREIGN KEY([SourceAppId])
REFERENCES [dbo].[SourceApps] ([SourceAppId])
GO
ALTER TABLE [dbo].[SEntries] CHECK CONSTRAINT [FK_SEntries_SourceApps]
GO
Turns out that Entity Framework will assume that any class that inherits from a POCO class that is mapped to a table on the database requires a Discriminator column, even if the derived class will not be saved to the DB.
The solution is quite simple and you just need to add [NotMapped] as an attribute of the derived class.
Example:
class Person
{
public string Name { get; set; }
}
[NotMapped]
class PersonViewModel : Person
{
public bool UpdateProfile { get; set; }
}
Now, even if you map the Person class to the Person table on the database, a "Discriminator" column will not be created because the derived class has [NotMapped].
As an additional tip, you can use [NotMapped] to properties you don't want to map to a field on the DB.
Here is the Fluent API syntax.
http://blogs.msdn.com/b/adonet/archive/2010/12/06/ef-feature-ctp5-fluent-api-samples.aspx
class Person
{
public string FirstName { get; set; }
public string LastName { get; set; }
public string FullName {
get {
return this.FirstName + " " + this.LastName;
}
}
}
class PersonViewModel : Person
{
public bool UpdateProfile { get; set; }
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
// ignore a type that is not mapped to a database table
modelBuilder.Ignore<PersonViewModel>();
// ignore a property that is not mapped to a database column
modelBuilder.Entity<Person>()
.Ignore(p => p.FullName);
}
I just encountered this and my problem was caused by having two entities both with the System.ComponentModel.DataAnnotations.Schema.TableAttribute referring to the same table.
for example:
[Table("foo")]
public class foo
{
// some stuff here
}
[Table("foo")]
public class fooExtended
{
// more stuff here
}
changing the second one from foo to foo_extended fixed this for me and I'm now using Table Per Type (TPT)
I had a similar problem, not exactly the same conditions and then i saw this post. Hope it helps someone. Apparently i was using one of my EF entity models a base class for a type that was not specified as a db set in my dbcontext. To fix this issue i had to create a base class that had all the properties common to the two types and inherit from the new base class among the two types.
Example:
//Bad Flow
//class defined in dbcontext as a dbset
public class Customer{
public int Id {get; set;}
public string Name {get; set;}
}
//class not defined in dbcontext as a dbset
public class DuplicateCustomer:Customer{
public object DuplicateId {get; set;}
}
//Good/Correct flow*
//Common base class
public class CustomerBase{
public int Id {get; set;}
public string Name {get; set;}
}
//entity model referenced in dbcontext as a dbset
public class Customer: CustomerBase{
}
//entity model not referenced in dbcontext as a dbset
public class DuplicateCustomer:CustomerBase{
public object DuplicateId {get; set;}
}
Another scenario where this occurs is when you have a base class and one or more subclasses, where at least one of the subclasses introduce extra properties:
class Folder {
[key]
public string Id { get; set; }
public string Name { get; set; }
}
// Adds no props, but comes from a different view in the db to Folder:
class SomeKindOfFolder: Folder {
}
// Adds some props, but comes from a different view in the db to Folder:
class AnotherKindOfFolder: Folder {
public string FolderAttributes { get; set; }
}
If these are mapped in the DbContext like below, the "'Invalid column name 'Discriminator'" error occurs when any type based on Folder base type is accessed:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Folder>().ToTable("All_Folders");
modelBuilder.Entity<SomeKindOfFolder>().ToTable("Some_Kind_Of_Folders");
modelBuilder.Entity<AnotherKindOfFolder>().ToTable("Another_Kind_Of_Folders");
}
I found that to fix the issue, we extract the props of Folder to a base class (which is not mapped in OnModelCreating()) like so - OnModelCreating should be unchanged:
class FolderBase {
[key]
public string Id { get; set; }
public string Name { get; set; }
}
class Folder: FolderBase {
}
class SomeKindOfFolder: FolderBase {
}
class AnotherKindOfFolder: FolderBase {
public string FolderAttributes { get; set; }
}
This eliminates the issue, but I don't know why!
I get the error in another situation, and here are the problem and the solution:
I have 2 classes derived from a same base class named LevledItem:
public partial class Team : LeveledItem
{
//Everything is ok here!
}
public partial class Story : LeveledItem
{
//Everything is ok here!
}
But in their DbContext, I copied some code but forget to change one of the class name:
public class MFCTeamDbContext : DbContext
{
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//Other codes here
modelBuilder.Entity<LeveledItem>()
.Map<Team>(m => m.Requires("Type").HasValue(ItemType.Team));
}
public class ProductBacklogDbContext : DbContext
{
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//Other codes here
modelBuilder.Entity<LeveledItem>()
.Map<Team>(m => m.Requires("Type").HasValue(ItemType.Story));
}
Yes, the second Map< Team> should be Map< Story>.
And it cost me half a day to figure it out!
Old Q, but for posterity...it also also happens (.NET Core 2.1) if you have a self-referencing navigation property ("Parent" or "Children" of the same type) but the Id property name isn't what EF expects. That is, I had an "Id" property on my class called WorkflowBase, and it had an array of related child steps, which were also of type WorkflowBase, and it kept trying to associate them with a non-existent "WorkflowBaseId" (the name i suppose it prefers as a natural/conventional default). I had to explicitly configure it using HasMany(), WithOne(), and HasConstraintName() to tell it how to traverse. But I spent a few hours thinking the problem was in 'locally' mapping the object's primary key, which i attempted to fix a bunch of different ways but which was probably always working.
this error happen with me because I did the following
I changed Column name of table in database
(I did not used Update Model from database in Edmx) I Renamed manually Property name to match the change in database schema
I did some refactoring to change name of the property in the class to be the same as database schema and models in Edmx
Although all of this, I got this error
so what to do
I Deleted the model from Edmx
Right Click and Update Model from database
this will regenerate the model, and entity framework will not give you this error
hope this help you