code first with abstract class, the fk couldn't generated - entity-framework

please look at the code below.
class Program
{
static void Main(string[] args)
{
using (myContext context = new myContext())
{
Team t = new Team();
t.id = 1;
t.Name = "asd";
context.teamSet.Add(t);
context.SaveChanges();
}
}
}
public abstract class Base
{
public virtual int id { get; set; }
}
public abstract class Player : Base
{
public virtual string Name { get; set; }
public virtual int Number { get; set; }
public virtual Team team { get; set; }
[ForeignKey("team")]
public int teamId { get; set; }
}
public class Team : Base
{
public ICollection<Player> Players { get; set; }
public string Name { get; set; }
}
public class FootballPlayer : Player
{
public double Speed { get; set; }
}
public class BasketballPlayer : Player
{
public double Height { get; set; }
public double Speed { get; set; }
}
public class myContext : DbContext
{
public DbSet<Player> playerSet { get; set; }
public DbSet<Team> teamSet { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Configurations.Add(new BaseConfiguration()).Add(new PlayerConfiguration()).Add(new TeamConfiguration()).Add(new FootballConfiguration()).Add(new BasketballConfiguration());
}
}
public class BaseConfiguration : EntityTypeConfiguration<Base>
{
public BaseConfiguration()
{
HasKey(k => k.id);
Property(p => p.id).IsRequired().HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);
}
}
public class PlayerConfiguration : EntityTypeConfiguration<Player>
{
public PlayerConfiguration()
{
Map(p=>{
p.MapInheritedProperties();
p.ToTable("Player");
});
}
}
public class TeamConfiguration : EntityTypeConfiguration<Team>
{
public TeamConfiguration()
{
Map(p =>
{
p.MapInheritedProperties();
p.ToTable("Team");
});
}
}
public class FootballConfiguration : EntityTypeConfiguration<FootballPlayer>
{
public FootballConfiguration()
{
ToTable("FootballPlayer");
}
}
public class BasketballConfiguration : EntityTypeConfiguration<BasketballPlayer>
{
public BasketballConfiguration()
{
ToTable("BasketballPlayer");
}
}
My Player class and Team Class are derived from Based Class, and FootballPlayer and BasketballPlayer are derived from Player. But in the generated database, Player table doesn't contain a FK teamId, it is only a common property. Furthermore, the FootballPlayer and BasketballPlayer tables don't contains the properties which derived from Player class. Anyone can help?

What inheritance mapping are you trying to achieve? At the moment you have TPC between Base and Player and TPT between Player and its derived types. If you want to have inherited properties in those derived types you must use TPC as well but in such case there should be no Player table in your database. To use TPC for player you must use MapInheritedProperties in their mapping configurations.

Related

Including a Model from different DbContext

I am not sure how to achieve the relation between 2 DbContexts. PurchaseOrderDbContext is a Code first approach & AgencyDbContext is an existing database. How can I include the "Division" from AgencyDbContext based on PurchaseOrder DivisionId?
To start off here is a very simplified version of my code.
Purchase Order Model
namespace Website.Models.PurchaseOrders
{
public class PurchaseOrder
{
public int ID { get; set; }
public DateTime OrderDate { get; set; }
public string Name { get; set; }
public int DivisionId { get; set; }
public int StatusID { get; set; }
public Agency.Division Division { get; set; }
}
}
Division Model (this is in a different DbContext)
namespace Website.Models.Agency
{
public class Division
{
public int DivisionId { get; set; }
public string DivisionName { get; set; }
public string DivisionShortName { get; set; }
public string DivisionAbbrev { get; set; }
public int? DivisionDirectorEmpId { get; set; }
}
}
Agency DbContext
namespace Website.Models.Agency
{
public class AgencyDbContext : DbContext
{
public Agency DbContext(DbContextOptions<AgencyDbContext> options) : base(options)
{
}
public virtual DbSet<Division> Division { get; set; }
public virtual DbSet<Section> Section { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
}
}
}
PurchaseOrderDbContext
namespace Website.Models.PurchaseOrders
{
public class PurchaseOrderDbContext : DbContext
{
public PurchaseOrderDbContext(DbContextOptions<PurchaseOrderDbContext> options) : base(options)
{}
public DbSet<Status> Statuses { get; set; }
public DbSet<PurchaseOrder> PurchaseOrder { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
}
}
}
I get an the error InvalidOperationException: Lambda expression used inside Include is not valid. This is referring to the Include extension on Division.
var purchaseOrder = _context.PurchaseOrder
.Include(p => p.Division)
.Include(p => p.Status)
.OrderByDescending(p => p.OrderDate);
Thank you in advance!
Probably the only way to resolve is to make a query to the first context for items you are looking for, and then populate Division property with entries from second context
public class PurchaseOrderService
{
private readonly PurchaseOrderDbContext purchaseOrderDbContext;
private readonly AgencyDbContext agencyDbContext;
public PurchaseOrderService(PurchaseOrderDbContext purchaseOrderDbContext,
AgencyDbContext agencyDbContext)
{
this.purchaseOrderDbContext = purchaseOrderDbContext;
this.agencyDbContext = agencyDbContext;
}
public PurchaseOrder Get(int id)
{
var purchaseOrder = purchaseOrderDbContext.PurchaseOrder.FirstOrDefault(x => x.ID == id);
if (purchaseOrder == null)
{
return null;
}
purchaseOrder.Division = agencyDbContext.Division.FirstOrDefault(x => x.DivisionId == purchaseOrder.DivisionId);
return purchaseOrder;
}
}

Dependency injection not working in web api call

Hi I am trying to build angular 2 web application using WebAPI, Entityframework that is loosely coupled using dependency injection. I am using unity for dependency injection. I have created multiple projects in one solution to address the separation concerns.
I have configured the dependency in unity.config however when i execute the webapi application and type the following url http://localhost:8702/api/allcustomers , I get message saying the customer controller doesn't have parameter-less constructor. I have set my break points in unity.config which never get hit
I would like to to understand if my implementation is correct as well
Below is the structure of my solution
CustomerOrder.Business.Objects
CustomerOrder.Data.Objects (references the business object)
CustomerOrder.Service.Api (references business object and service implementation)
CustomerOrder.Service.Implementation (references business objects and data objects)
CustomerOrder.Web (Yet to implement)
Below is the code
CustomerOrder.Business.Objects
public class Customer
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Gender { get; set; }
public string Email { get; set; }
public string Address { get; set; }
public string City { get; set; }
public string State { get; set; }
public int? Zip { get; set; }
}
CustomerOrder.Data.Objects
public class CustomerDao : ICustomerDao
{
IEnumerable<CustomerOrder.BusinessObjects.Customer> ICustomerDao.GetAllCustomers()
{
using (var customerOrderContext = new Entities())
{
return (from customer in customerOrderContext.Customers
select new CustomerOrder.BusinessObjects.Customer
{
Id = customer.Id,
FirstName = customer.FirstName,
LastName = customer.LastName,
Address = customer.Address,
City = customer.City,
Email = customer.Email,
Gender = customer.Gender,
State = customer.State,
Zip = customer.Zip
}).ToList();
}
}
}
public interface ICustomerDao
{
/// <summary>
/// Get All Customers
/// </summary>
/// <returns></returns>
IEnumerable<Customer> GetAllCustomers();
}
public interface IDaoFactory
{
ICustomerDao CustomerDao { get; }
}
}
public class DaoFactory : IDaoFactory
{
public DaoFactory(ICustomerDao CustomerDao, IProductDao ProductDao, IOrderDao OrderDao)
{
this.CustomerDao = CustomerDao;
}
public ICustomerDao CustomerDao { set; get; }
}
CustomerOrder.Service.Api
Unity.Config
public static void RegisterComponents()
{
var container = new UnityContainer();
// register all your components with the container here
// it is NOT necessary to register your controllers
// e.g. container.RegisterType<ITestService, TestService>();
container.RegisterType<ICustomerProvider, CustomerProvider>();
container.RegisterType<IOrderProvider, OrderProvider>();
container.RegisterType<IProductProvider, ProductProvider>();
GlobalConfiguration.Configuration.DependencyResolver = new UnityDependencyResolver(container);
}
CustomerController.cs
public class CustomerController : ApiController
{
private ICustomerProvider customerProvider;
public CustomerController(ICustomerProvider customerProvider)
{
this.customerProvider = customerProvider;
}
[Route("api/allcustomers")]
public IEnumerable<Customer> GetAllCustomers()
{
return customerProvider.GetAllCustomers();
}
CustomerOrder.Service.Implementation
public interface ICustomerProvider
{
IEnumerable<BusinessObjects.Customer> GetAllCustomers();
}
public class CustomerProvider : ICustomerProvider
{
private readonly IDaoFactory dataAccess;
public CustomerProvider(IDaoFactory dalFactory)
{
this.dataAccess = dalFactory;
}
public IEnumerable<BusinessObjects.Customer> GetAllCustomers()
{
IList<BusinessObjects.Customer> customerCollection = new List<BusinessObjects.Customer>();
dataAccess.CustomerDao.GetAllCustomers();
return customerCollection;
}
}
Context Class
namespace CustomerOrderData.EF
{
using System;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
public partial class Entities : DbContext
{
public Entities()
: base("name=Entities")
{
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
// throw new UnintentionalCodeFirstException();
}
public virtual DbSet<Customer> Customers { get; set; }
public virtual DbSet<OrderDetail> OrderDetails { get; set; }
public virtual DbSet<Order> Orders { get; set; }
public virtual DbSet<Product> Products { get; set; }
}
}
In CustomerProvider, the IDaoFactory is probably not getting resolved because it's not registered. Add this to the Unity.Config:
container.RegisterType<IDaoFactory , DaoFactory >();
Please try including a parameterless constructor into the customer controller.
public CustomerController() {}
You should register not only IDaoFactory and his constructor dependencies
container.RegisterType<IDaoFactory, DaoFactory>();
container.RegisterType<ICustomerDao, CustomerDao>();
container.RegisterType<IOrderDao, OrderDao>();
container.RegisterType<IProductDao, ProductDao>();

Entity framework replaces delete+insert with an update. How to turn it off

I want to remove a row in database and insert it again with the same Id, It sounds ridiculous, but here is the scenario:
The domain classes are as follows:
public class SomeClass
{
public int SomeClassId { get; set; }
public string Name { get; set; }
public virtual Behavior Behavior { get; set; }
}
public abstract class Behavior
{
public int BehaviorId { get; set; }
}
public class BehaviorA : Behavior
{
public string BehaviorASpecific { get; set; }
}
public class BehaviorB : Behavior
{
public string BehaviorBSpecific { get; set; }
}
The entity context is
public class TestContext : DbContext
{
public DbSet<SomeClass> SomeClasses { get; set; }
public DbSet<Behavior> Behaviors { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
modelBuilder.Entity<SomeClass>()
.HasOptional(s => s.Behavior)
.WithRequired()
.WillCascadeOnDelete(true);
}
}
Now this code can be executed to demonstrate the point
(described with comments in the code below)
using(TestContext db = new TestContext())
{
var someClass = new SomeClass() { Name = "A" };
someClass.Behavior = new BehaviorA() { BehaviorASpecific = "Behavior A" };
db.SomeClasses.Add(someClass);
// Here I have two classes with the state of added which make sense
var modifiedEntities = db.ChangeTracker.Entries()
.Where(entity => entity.State != System.Data.Entity.EntityState.Unchanged).ToList();
// They save with no problem
db.SaveChanges();
// Now I want to change the behavior and it causes entity to try to remove the behavior and add it again
someClass.Behavior = new BehaviorB() { BehaviorBSpecific = "Behavior B" };
// Here it can be seen that we have a behavior A with the state of deleted and
// behavior B with the state of added
modifiedEntities = db.ChangeTracker.Entries()
.Where(entity => entity.State != System.Data.Entity.EntityState.Unchanged).ToList();
// But in reality when entity sends the query to the database it replaces the
// remove and insert with an update query (this can be seen in the SQL Profiler)
// which causes the discrimenator to remain the same where it should change.
db.SaveChanges();
}
How to change this entity behavior so that delete and insert happens instead of the update?
A possible solution is to make the changes in 2 different steps: before someClass.Behavior = new BehaviorB() { BehaviorBSpecific = "Behavior B" }; insert
someClass.Behaviour = null;
db.SaveChanges();
The behaviour is related to the database model. BehaviourA and B in EF are related to the same EntityRecordInfo and has the same EntitySet (Behaviors).
You have the same behaviour also if you create 2 different DbSets on the context because the DB model remains the same.
EDIT
Another way to achieve a similar result of 1-1 relationship is using ComplexType. They works also with inheritance.
Here an example
public class TestContext : DbContext
{
public TestContext(DbConnection connection) : base(connection, true) { }
public DbSet<Friend> Friends { get; set; }
public DbSet<LessThanFriend> LessThanFriends { get; set; }
}
public class Friend
{
public Friend()
{Address = new FullAddress();}
public int Id { get; set; }
public string Name { get; set; }
public FullAddress Address { get; set; }
}
public class LessThanFriend
{
public LessThanFriend()
{Address = new CityAddress();}
public int Id { get; set; }
public string Name { get; set; }
public CityAddress Address { get; set; }
}
[ComplexType]
public class CityAddress
{
public string Cap { get; set; }
public string City { get; set; }
}
[ComplexType]
public class FullAddress : CityAddress
{
public string Street { get; set; }
}

Entity Framework: One to one issue in TPC hierarchy

I have a TPC hierarchy like this:
public abstract class Base
{
public Guid BaseId { get; set; }
public string BaseName { get; set; }
}
public class Sub1 : Base
{
public Sub2 Vender { get; set; }
}
public class Sub2 : Base
{
public Sub1 Customer { get; set; }
}
public class MyDbContext : DbContext
{
public MyDbContext()
: base("name=db")
{ }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<Sub1>().HasRequired(x => x.Vender).WithOptional(x => x.Customer);
modelBuilder.Entity<Sub1>().Map(x =>
{
x.ToTable("Sub1s");
x.MapInheritedProperties();
}).HasKey(x => x.BaseId);
modelBuilder.Entity<Sub2>().Map(x =>
{
x.ToTable("Sub2s");
x.MapInheritedProperties();
}).HasKey(x => x.BaseId);
}
public DbSet<Base> People { get; set; }
public DbSet<Sub2> Venders { get; set; }
public DbSet<Sub1> Customers { get; set; }
}
Then I run the code and EF create tables (Sub1s and Sub2s).
But EF create an aditional Foreign Key for table Sub1, it do not use the Key of Sub1 as the Foreign Key..It generates an additional FK named Vender_BaseId..

Table per Concrete Type Mapping Issue in EF Code First 4.2

I'm getting a EntityType 'User' has no key defined. Define the key for this EntityType error.
Model:
public abstract class KeyedEntityBase
{
public int ID { get; private set; }
}
public class User : KeyedEntityBase
{
public string UserName { get; private set; }
public string EmailAddress { get; private set; }
}
Context:
public class LSBPortalContext : DbContext
{
public LSBPortalContext()
: base("LSBPortalDB")
{
}
public DbSet<User> Users { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<User>().Map(m =>
{
m.MapInheritedProperties();
m.ToTable("User");
});
base.OnModelCreating(modelBuilder);
}
}
The issues was that I didn't actually map the KeyedEntityBase class. Once I did that it all worked properly.