Owned Entity Collections usage - ef-core-2.2

When I run the following code I get an exception saying that "The entity type 'ElementWeight' requires a primary key to be defined". Why do I need a key if I want to treat ElementWeight as a value-type?
var context = new DataContext(options);
context.Weightings.Add(new ImportWeighting { Name="temp", Weights = new List<ElementWeight>
{ new ElementWeight { Mag_dB = 1.0, Phase_deg = 10.0 },
new ElementWeight { Mag_dB = 2.0, Phase_deg = 20.0 }
} });
In the OnModelCreating I do the following
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<ImportWeighting>().OwnsMany(c => c.Weights);
}
And here are the classes
public class ImportWeighting
{
public int Id { get; set; }
public string Name { get; set; }
public List<ElementWeight> Weights { get; set; }
}
public class ElementWeight
{
public double Mag_dB { get; set; }
public double Phase_deg { get; set; }
}
If I add a key as the documentations shows then I get an error that the items already exists
modelBuilder.Entity<Distributor>().OwnsMany(p => p.ShippingCenters, a =>
{
a.HasForeignKey("DistributorId");
a.Property<int>("Id");
a.HasKey("DistributorId", "Id");
});

Related

Entity Framework Change Tracking And Automapper

Entity Framework classes:
namespace ORM
{
public class Car
{
public int Id { get; set; }
public string Name { get; set; }
public int Price { get; set; }
public virtual List<Wheel> Wheels { get; set; }
}
public class Wheel
{
public int Id { get; set; }
public double Size { get; set; }
public virtual Car Car { get; set; }
}
}
namespace DAL.Entities
{
public class Car
{
public int Id { get; set; }
public string Name { get; set; }
public int Price { get; set; }
public List<Wheel> Wheels { get; set; }
}
public class Wheel
{
public int Id { get; set; }
public double Size { get; set; }
public Car Car { get; set; }
}
}
ORM and DAL models.
Automapper configuration is:
public class DalProfile : Profile
{
public DalProfile()
{
CreateMap<Wheel, Entities.Wheel>()
.ForMember(m => m.Car, opt => opt.Ignore());
CreateMap<Entities.Wheel, Wheel>()
.ForMember(m => m.Car, opt => opt.Ignore());
CreateMap<Car, Entities.Car>()
.AfterMap((src, dest) =>
{
foreach (var wheel in dest.Wheels)
{
wheel.Car = dest;
}
});
CreateMap<Entities.Car, Car>()
.AfterMap((src, dest) =>
{
foreach (var wheel in dest.Wheels)
{
wheel.Car = dest;
}
});
CreateMap<Wheel, Wheel>()
.ForMember(m => m.Car, opt => opt.Ignore());
CreateMap<Car, Car>()
.AfterMap((src, dest) =>
{
foreach (var wheel in dest.Wheels)
{
wheel.Car = dest;
}
});
}
}
Repository class:
public class CarRepository
{
private readonly DbContext context;
public CarRepository(DbContext context)
{
this.context = context;
}
public void Update<T>(int id, T newCar) where T : class
{
var entity = context.Set<T>().Find(id);
Mapper.Map(newCar, entity);
context.SaveChanges();
}
}
Main entry:
static void Main(string[] args)
{
Mapper.Initialize(cfg => cfg.AddProfile(new DalProfile()));
DataContext context = new DataContext();
CarRepository carRepository = new CarRepository(context);
Car car = carRepository.Get(120);
DAL.Entities.Car dalCar = Mapper.Map<Car, DAL.Entities.Car(car);
dalCar.Name = "ew";
dalCar.Wheels[0].Size = 1994;
Car ormCar = Mapper.Map<DAL.Entities.Car, Car>(dalCar);
carRepository.Update(ormCar.Id, ormCar);
}
In my project i have ORM, DAL layers. Inside Update method i want to update only changed values. Of course if do changes with ORM.Car directly like this:
public void Update<T>(ORM.Car car) where T : class
{
var entity = context.Set<Car>().Find(car.id);
entity.Name = "New name";
entity.Wheels[0].Size = 1111;
context.SaveChanges();
}
This works great. Entity framework can update only Name property and related Wheel object.
But in my project i have different layers. So i want to change some properties of DAL.Car than map this object to ORM.Car with Automapper and apply changes like i did with ORM.Car above. But after mapping with Automapper i can't do this cause of Automapper creates new objects after mapping and Entity Framework can't update only needed properties like with ORM.Car directly cause of Dynamic Proxies maybe or i don't know. I want generic Update which looks something like this:
public void Update<T>(int id, T newCar) where T : class
{
var entity = context.Set<T>().Find(id);
Mapper.Map(newCar, entity);
context.SaveChanges();
}
Where newCar is a Car which is converted from DAL.Car;
Can i do this?

Trouble with EF6 inserts

I am in the process of Downgrading from EF7 to EF6 due to business decisions. I have looked at several examples but cannot seem to get it to work.
Here is what I have for EF 7
Context:
public class OwnerContext : DbContext
{
protected override void OnConfiguring(DbContextOptionsBuilder options)
{
options.UseSqlServer(#"Server=server\testdbs;Database=test;Trusted_Connection=True;");
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Owner>(entity =>
{
entity.ToTable("Owner");
entity.Property(e => e.Id)
.HasMaxLength(50)
.HasColumnType("varchar");
});
}
public virtual DbSet<Owner> Owner { get; set; }
}
Owner Model
public class Owner
{
public int OwnerId { get; set; }
public string Name { get; set; }
public int Age { get; set; }
}
How I use it
static void Main(string[] args)
{
using (var context = new OwnerContext())
{
var owner = new Owner
{
Name = "First Name",
Age = 4
};
context.Owner.Add(owner);
context.SaveChanges();
Console.ReadLine();
}
}
I got this to work with no issues and I get records in the data base. For EF 6 it is a little different
Here is what I have for EF6
Context
public class OwnerContext : DbContext
{
public OwnerContext(string connectionString) : base(connectionString) { }
public OwnerContext()
: this("OwnerConn")
{
}
public virtual DbSet<Owner> Owner{ get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
var owner = modelBuilder.Entity<Owner>().ToTable("Owner");
owner.Property(e => e.OwnerId)
.HasMaxLength(50)
.HasColumnType("varchar");
owner.HasKey(u => u.OwnerId);
}
}
Model
public class Owner
{
public int OwnerId { get; set; }
public string Name { get; set; }
public int Age { get; set; }
}
How I use it
static void Main(string[] args)
{
try
{
using (var context = new OwnerContext())
{
var person = new Owner
{
Name = "Test Name",
Age = 5
};
context.Owner.Add(person);
context.Entry(person).State = EntityState.Added;
context.SaveChanges();
}
}
catch (Exception exception)
{
Console.WriteLine(exception.Message);
}
Console.ReadLine();
}
ConnectionString
<connectionStrings>
<add name="OwnerConn" connectionString="Server=server\testdbs;Database=test;Trusted_Connection=True;" providerName="System.Data.SqlClient" />
</connectionStrings>
It seems to be very simple based on the tutorials. Hoever, I cant seem to get the changes to be reflected in the database. However, when I restart the console app and pull the records like this.
var rows = from a in context.Owner select a
It returns rows but I still don't see them in the DB. I'm out of ideas so hopefully someone can help.

NavigationProperty has wrong data

I have a very simple example I am trying to set up with the following schema...
public class Foo
{
public int Id { get; set; }
public string Name { get; set; }
public string SomethingVeryBig { get; set; }
public List<Bar> Bars { get; set; }
}
public class Bar
{
public int Id { get; set; }
public int FooId { get; set; }
public string Name { get; set; }
}
What I am trying to test is using Breeze in a way disconnected from my data repository, so I am hand coding from the Fluent API my DBContext. Context code below, "FoosDb" is just an sdf file deployed with the project for the Breeze Metadata and is not a real database we are saving data into.
public class FoosDbContext : DbContext
{
public FoosDbContext() : base(nameOrConnectionString: "FoosDb")
{
Database.SetInitializer<FoosDbContext>(null);
}
public DbSet<Foo> Foos { get; set; }
public DbSet<Bar> Bars { get; set; }
public DbSet<Link> Links { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Foo>().HasKey(f => f.Id);
modelBuilder.Entity<Bar>().HasKey(b => b.Id);
modelBuilder.Entity<Foo>().HasMany(f => f.Bars).WithRequired().HasForeignKey(b => b.FooId);
}
}
public class FoosContextProvider : EFContextProvider<FoosDbContext>
{
public FoosContextProvider() : base() { }
protected override List<KeyMapping> SaveChangesCore(Dictionary<Type, List<EntityInfo>> saveMap)
{
return new List<KeyMapping>();
}
protected override bool BeforeSaveEntity(EntityInfo entityInfo)
{
return true;
}
protected override Dictionary<Type, List<EntityInfo>> BeforeSaveEntities(Dictionary<Type, List<EntityInfo>> saveMap)
{
// return a map of those entities we want saved.
return saveMap;
}
}
Everything works great and I am testing all CRUD operations via a project from the Hot Towel Template, but when I query Foos from my controller the json data looks perfect, but when it gets transferred to Breeze/Knockout Observables the data in each "Foo.Bars" list is wrong. It is taking Bar.Id = 1 and always putting that on Foo.Id = 1, Bar.Id = 2 and putting that on Foo.Id = 2, and so on. Even though in my example Bar.Id = 2 should be on Foo.Id = 1.

Id's not updating when using EntityFramework code-first

after an earlier question i'm stil struggling with EF Code-First;
I have 3 (in this example, in practice there are more) where 1 table uses multiple Id's for accessing other tables.
I have 2 problems
1: the Id's for shipping and delivery aren't set (remain '0') when saving to the database.
2: when using DBMigrations an index is created twice for the RecordId
.Index(t => t.RecordId),
.Index(t => t.RecordId);
code example:
Record Class:
public class Record
{
public Record()
{
Shipping = new Shipping();
Delivery = new Delivery();
}
public int RecordId { get; set; }
public int ShippingId { get; set; }
public int DeliveryId { get; set; }
public virtual Shipping Shipping { get; set; }
public virtual Delivery Delivery { get; set; }
}
Shipping Class:
public class Shipping
{
public int ShippingId { get; set; }
public string ShippingName { get; set; }
public virtual Record Record { get; set; }
}
Delivery Class:
public class Delivery
{
public int DeliveryId { get; set; }
public String DeliveryText { get; set; }
public virtual Record Record { get; set; }
}
context:
public class Context : DbContext
{
public DbSet<Record> Records { get; set; }
public DbSet<Shipping> Shippings { get; set; }
public DbSet<Delivery> Deliveries { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Record>()
.HasRequired(m => m.Shipping)
.WithRequiredDependent(x => x.Record)
.WillCascadeOnDelete(false);
modelBuilder.Entity<Record>()
.HasRequired(m => m.Delivery)
.WithRequiredDependent(x => x.Record)
.WillCascadeOnDelete(false);
base.OnModelCreating(modelBuilder);
}
Main program (method):
using (Context context = new Context())
{
var model = context.Records.Create();
var shipping = model.Shipping;
shipping.ShippingName = "TestContext";
var delivery = model.Delivery;
delivery.DeliveryText = "customText";
context.Entry(model).State = EntityState.Added;
context.SaveChanges();
}
Main program (second try)
using (Context context = new Context())
{
var model = context.Records.Create();
model.Shipping = context.Shippings.Create();
var shipping = model.Shipping;
shipping.ShippingName = "TestContext";
model.Delivery = context.Deliveries.Create();
var delivery = model.Delivery;
delivery.DeliveryText = "customText";
context.Entry(model).State = EntityState.Added;
context.SaveChanges();
}
TO avoid the extra index, don't specify the key fields in your record class.
To get the default Identity behaviour name the key fields Id
public class Record
{
public Record()
{
Shipping = new Shipping();
Delivery = new Delivery();
}
public int Id { get; set; }
public virtual Shipping Shipping { get; set; }
public virtual Delivery Delivery { get; set; }
}

Can automapper map a foreign key to an object using a repository?

I'm trying out Entity Framework Code first CTP4. Suppose I have:
public class Parent
{
public int Id { get; set; }
public string Name { get; set; }
}
public class Child
{
public int Id { get; set; }
public string Name { get; set; }
public Parent Mother { get; set; }
}
public class TestContext : DbContext
{
public DbSet<Parent> Parents { get; set; }
public DbSet<Child> Children { get; set; }
}
public class ChildEdit
{
public int Id { get; set; }
public string Name { get; set; }
public int MotherId { get; set; }
}
Mapper.CreateMap<Child, ChildEdit>();
Mapping to the Edit model is not a problem. On my screen I select the mother through some control (dropdownlist, autocompleter, etc) and the Id of the mother gets posted in back:
[HttpPost]
public ActionResult Edit(ChildEdit posted)
{
var repo = new TestContext();
var mapped = Mapper.Map<ChildEdit, Child>(posted); // <------- ???????
}
How should I solve the last mapping? I don't want to put Mother_Id in the Child object. For now I use this solution, but I hope it can be solved in Automapper.
Mapper.CreateMap<ChildEdit, Child>()
.ForMember(i => i.Mother, opt => opt.Ignore());
var mapped = Mapper.Map<ChildEdit, Child>(posted);
mapped.Mother = repo.Parents.Find(posted.MotherId);
EDIT
This works, but now I have to do that for each foreign key (BTW: context would be injected in final solution):
Mapper.CreateMap<ChildEdit, Child>();
.ForMember(i => i.Mother,
opt => opt.MapFrom(o =>
new TestContext().Parents.Find(o.MotherId)
)
);
What I'd really like would be:
Mapper.CreateMap<int, Parent>()
.ForMember(i => i,
opt => opt.MapFrom(o => new TestContext().Parents.Find(o))
);
Mapper.CreateMap<ChildEdit, Child>();
Is that possible with Automapper?
First, I'll assume that you have a repository interface like IRepository<T>
Afterwards create the following class:
public class EntityConverter<T> : ITypeConverter<int, T>
{
private readonly IRepository<T> _repository;
public EntityConverter(IRepository<T> repository)
{
_repository = repository;
}
public T Convert(ResolutionContext context)
{
return _repository.Find(System.Convert.ToInt32(context.SourceValue));
}
}
Basically this class will be used to do all the conversion between an int and a domain entity. It uses the "Id" of the entity to load it from the Repository. The IRepository will be injected into the converter using an IoC container, but more and that later.
Let's configure the AutoMapper mapping using:
Mapper.CreateMap<int, Mother>().ConvertUsing<EntityConverter<Mother>>();
I suggest creating this "generic" mapping instead so that if you have other references to "Mother" on other classes they're mapped automatically without extra-effort.
Regarding the Dependency Injection for the IRepository, if you're using Castle Windsor, the AutoMapper configuration should also have:
IWindsorContainer container = CreateContainer();
Mapper.Initialize(map => map.ConstructServicesUsing(container.Resolve));
I've used this approach and it works quite well.
Here's how I did it: (using ValueInjecter)
I made the requirements a little bigger just to show how it works
[TestFixture]
public class JohnLandheer
{
[Test]
public void Test()
{
var child = new Child
{
Id = 1,
Name = "John",
Mother = new Parent { Id = 3 },
Father = new Parent { Id = 9 },
Brother = new Child { Id = 5 },
Sister = new Child { Id = 7 }
};
var childEdit = new ChildEdit();
childEdit.InjectFrom(child)
.InjectFrom<EntityToInt>(child);
Assert.AreEqual(1, childEdit.Id);
Assert.AreEqual("John", childEdit.Name);
Assert.AreEqual(3, childEdit.MotherId);
Assert.AreEqual(9, childEdit.FatherId);
Assert.AreEqual(5, childEdit.BrotherId);
Assert.AreEqual(7, childEdit.SisterId);
Assert.AreEqual(0, childEdit.Sister2Id);
var c = new Child();
c.InjectFrom(childEdit)
.InjectFrom<IntToEntity>(childEdit);
Assert.AreEqual(1, c.Id);
Assert.AreEqual("John", c.Name);
Assert.AreEqual(3, c.Mother.Id);
Assert.AreEqual(9, c.Father.Id);
Assert.AreEqual(5, c.Brother.Id);
Assert.AreEqual(7, c.Sister.Id);
Assert.AreEqual(null, c.Sister2);
}
public class Entity
{
public int Id { get; set; }
}
public class Parent : Entity
{
public string Name { get; set; }
}
public class Child : Entity
{
public string Name { get; set; }
public Parent Mother { get; set; }
public Parent Father { get; set; }
public Child Brother { get; set; }
public Child Sister { get; set; }
public Child Sister2 { get; set; }
}
public class ChildEdit
{
public int Id { get; set; }
public string Name { get; set; }
public int MotherId { get; set; }
public int FatherId { get; set; }
public int BrotherId { get; set; }
public int SisterId { get; set; }
public int Sister2Id { get; set; }
}
public class EntityToInt : LoopValueInjection
{
protected override bool TypesMatch(Type sourceType, Type targetType)
{
return sourceType.IsSubclassOf(typeof(Entity)) && targetType == typeof(int);
}
protected override string TargetPropName(string sourcePropName)
{
return sourcePropName + "Id";
}
protected override bool AllowSetValue(object value)
{
return value != null;
}
protected override object SetValue(object sourcePropertyValue)
{
return (sourcePropertyValue as Entity).Id;
}
}
public class IntToEntity : LoopValueInjection
{
protected override bool TypesMatch(Type sourceType, Type targetType)
{
return sourceType == typeof(int) && targetType.IsSubclassOf(typeof(Entity));
}
protected override string TargetPropName(string sourcePropName)
{
return sourcePropName.RemoveSuffix("Id");
}
protected override bool AllowSetValue(object value)
{
return (int)value > 0;
}
protected override object SetValue(object sourcePropertyValue)
{
// you could as well do repoType = IoC.Resolve(typeof(IRepo<>).MakeGenericType(TargetPropType))
var repoType = typeof (Repo<>).MakeGenericType(TargetPropType);
var repo = Activator.CreateInstance(repoType);
return repoType.GetMethod("Get").Invoke(repo, new[] {sourcePropertyValue});
}
}
class Repo<T> : IRepo<T> where T : Entity, new()
{
public T Get(int id)
{
return new T{Id = id};
}
}
private interface IRepo<T>
{
T Get(int id);
}
}
It's possible to define the foreign key in EF this way as well:
[ForeignKey("MotherId")]
public virtual Parent Mother { get; set; }
public int MotherId { get; set; }
In this case, It's not necessary to do an extra query to find the Mother. Just Assign the ViewModel's MotherId to the Model's MotherId.

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