I have a simple entity class with a list of base classes, which is ignored in the model:
public class MyClass
{
public int Id {get;set;}
public List<BaseChild> BaseChildren {get; set;}
}
Which has this configuration:
public class MyClassConfiguration : IEntityTypeConfiguration<MyClass>
{
public void Configure(EntityTypeBuilder<MyClass> builder)
{
builder.Property(o => o.Id).UseHiLo();
builder.HasKey(o => o.Id);
builder.Ignore(o => o.BaseChildren);
}
}
I have classes that inherit from BaseChild and they all use this configuration:
public abstract class BaseChild
{
public int MyClassId { get; set; }
}
public abstract class BaseChildConfiguration<T> : IEntityTypeConfiguration<T> where T : BaseChild
{
public virtual void Configure(EntityTypeBuilder<T> builder)
{
builder.HasKey(o => o.MyClassId);
builder.HasOne<MyClass>()
.WithOne()
.HasForeignKey<T>(o => o.MyClassId);
}
}
public class Instance : Component
{
public long Code { get; set; }
}
public class InstanceConfiguration : BaseChildConfiguration<Instance>
{
}
All the configurations are properly being applied in my OnModelCreating:
protected override void OnModelCreating(ModelBuilder mb)
{
mb.ApplyConfigurationsFromAssembly(Assembly.GetExecutingAssembly());
}
Yet for some reason I keep getting the following exception:
A key cannot be configured on 'Instance' because it is a derived type. The key must be configured on the root type 'BaseChild'. If you did not intend for 'BaseChild' to be included in the model, ensure that it is not included in a DbSet property on your context, referenced in a configuration call to ModelBuilder, or referenced from a navigation property on a type that is included in the model.
Related
I have a TPH situation where I have an abstract base class and 8 derived classes from it by using a discriminator. Two of them share a list of sub classes.
public abstract class StepBase : FullAuditedEntity<Guid>
{
public int Order { get; set; }
public StepType StepType { get; set; }
}
The thing is I have two types which shares a SubClass
public class DestinationVesselStep : StepBase
{
public virtual List<DestinationVessel> VesselsDestination { get; set; }
}
public class LiquidNitrogenStep : StepBase
{
public virtual List<DestinationVessel> DestinationsBoxes { get; set; }
}
private static void ConfigureVesselsStep(ModelBuilder builder)
{
builder.Entity<DestinationVesselStep>(b =>
{
//Properties
b.HasMany(p => p.VesselsDestination).WithOne().HasForeignKey(x => x.StepId);
});
}
private static void ConfigureLiquidNitrogenStep(ModelBuilder builder)
{
builder.Entity<LiquidNitrogenStep>(b =>
{
//Properties
b.HasMany(p => p.DestinationsBoxes).WithOne().HasForeignKey(x => x.StepId);
});
}
But when I request a LiquidNitrogenStep with two or more destinationBoxes I get the following error:
System.InvalidOperationException : Sequence contains more than one element.
it works fine if I only have one destinationBox
I am expecting to get a LiquidNitrogenStep with all its destination boxes, the error do not happnd with DestinationVesselStep
DestinationVessel.StepId can't refer to both a DestinationVesselStep and LiquidNitrogenStep.
So either add separate foreign keys to DestinationVessel, eg LiquidNitrogenStepId, and DestinationVesselStepId, or make the relationships many-to-many, which uses separate linking tables for each relationship, instead of putting foreign keys on the target Entity.
private static void ConfigureVesselsStep(ModelBuilder builder)
{
builder.Entity<DestinationVesselStep>(b =>
{
//Properties
b.HasMany(p => p.VesselsDestination).WithMany( d => d.DestinationSteps);
});
}
private static void ConfigureLiquidNitrogenStep(ModelBuilder builder)
{
builder.Entity<LiquidNitrogenStep>(b =>
{
//Properties
b.HasMany(p => p.DestinationsBoxes).WithMany(d => d.LiquidNitrogenSteps);
});
}
I have an Order and an OrderState class, but I will implement state pattern, so I will have a base class State and derived classes for each state.
The classes would be this:
class Order
{
long Id;
Status State;
}
class Status
{
string abstract State;
public abstract void Method1();
}
class Status1 : Status
{
public Status1()
{
State = "Status1";
public ovderride Method1()
{
//do something
}
}
string override State;
}
class Status2 : Status
{
public Status1()
{
State = "Status2";
}
string override State;
public override void Method1()
{
// do something
}
}
In EF Core, I have a class to configure Order with Fluent API:
paramPedidoCompraConfiguracion
.OwnsOne(miOrder => miOrder.State, stateNavigationBuilder =>
{
sateNavigationBuilder.WithOwner();
stateNavigationBuilder.Property<string>(x => x.State)
.HasColumnName("State")
.HasColumnType("varchar(200)")
.IsRequired()
.IsUnicode(false)
.HasMaxLength(200);
});
}
But I get this error:
The corresponding CLR type for entity type 'Status' cannot be instantiated, and there is no derived entity type in the model that corresponds to a concrete CLR type.
I have read the documentation about this in Microsoft docs: https://learn.microsoft.com/en-us/ef/core/modeling/inheritance, in particular in the shared columns, because I want to share the column to avoid to have one column for each state.
This is the code in the documentation:
public class MyContext : DbContext
{
public DbSet<BlogBase> Blogs { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Blog>()
.Property(b => b.Url)
.HasColumnName("Url");
modelBuilder.Entity<RssBlog>()
.Property(b => b.Url)
.HasColumnName("Url");
}
}
public abstract class BlogBase
{
public int BlogId { get; set; }
}
public class Blog : BlogBase
{
public string Url { get; set; }
}
public class RssBlog : BlogBase
{
public string Url { get; set; }
}
It is defining a dbSet for the base blog, but in my case I am using the state as value object, not as identity, so if I am not wrong, I shouldn't to create a dbSet for values objects, only for entities. So if it is correct, I don't know how to configure my value object with derived classes.
How could I do it?
Thanks.
When using Entity Framework 5 Code First, with Table Per Hierarchy.
This combined with a Repository and Unit of Work (tried several implementations).
I'm having the following error:
(34,10) : error 3032: Problem in mapping fragments starting at lines 19, 34:EntityTypes T, T are being mapped to the same rows in table T. Mapping conditions can be used to distinguish the rows that these types are mapped to.
I have resolved this issue using the following guide:
Entity Framework 4.3 - TPH mapping and migration error
This works when using a general look-up of all records, then no errors.
When using the DBSet<T>.Find(id), I receive the above error message.
When using DBSet<T>.Where(t => t.id == id) all works fine.
Please does anyone have the solution for this problem?
public class TDataContext : DbContext
{
// Models
public abstract class BaseTrackable
{
public DateTime DateModified { get; set; }
}
public abstract class ParentClass : BaseTrackable
{
public int ParentId { get; set; }
public string ParentString { get; set; }
}
public class Foo : ParentClass
{
public string FooString { get; set; }
}
public class Bar : ParentClass
{
public string BarString { get; set; }
}
// Configuration
public class ParentConfiguration : EntityTypeConfiguration<ParentClass>
{
public ParentConfiguration()
{
ToTable("Parent");
}
}
public class FooConfiguration : EntityTypeConfiguration<Foo>
{
public FooConfiguration()
{
Map(m => m.Requires("FooIndicator").HasValue(true));
}
}
public class BarConfiguration : EntityTypeConfiguration<Bar>
{
public BarConfiguration()
{
Map(m => m.Requires("BarIndicator").HasValue(true));
}
}
public DbSet<ParentClass> Parent { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Configurations
.Add(new ParentConfiguration())
.Add(new FooConfiguration())
.Add(new BarConfiguration());
}
}
public class Controller
{
TDataContext _context = new TDataContext();
// Repository function
public T GetById<T>(object id) where T : class
{
var dbset = _context.Set<T>();
return dbset.Find(id);
}
public IQueryable<TDataContext.Foo> GetFiltered(Expression<Func<TDataContext.Foo, bool>> filter)
{
var dbset = _context.Set<TDataContext.Foo>();
return dbset.Where(filter);
}
// Final call
// Which fails..
public TDataContext.Foo Get(int id)
{
return this.GetById<TDataContext.Foo>(id);
}
// This works...
public TDataContext.Foo GetWhere(int id)
{
return this.GetFiltered(f => f.ParentId == id).FirstOrDefault();
}
}
Found something that solves my problem partially...
When adding another indicator to the tables, there is no more error, example:
public class FooConfiguration : EntityTypeConfiguration<Foo>
{
public FooConfiguration()
{
Map(m => {
m.Requires("FooIndicator").HasValue(true);
m.Requires("BarIndicator").HasValue<short>(1);
});
}
}
public class BarConfiguration : EntityTypeConfiguration<Bar>
{
public BarConfiguration()
{
Map(m => {
m.Requires("BarIndicator").HasValue(true);
m.Requires("FooIndicator").HasValue<short>(0);
});
}
}
Wouldn't be better
public class FooConfiguration : EntityTypeConfiguration<Foo>
{
public FooConfiguration()
{
Map(m => m.Requires("Type").HasValue("Foo"));
}
}
public class BarConfiguration : EntityTypeConfiguration<Bar>
{
public BarConfiguration()
{
Map(m => m.Requires("Type").HasValue("Bar");
}
}
In this way FooConfiguration doesn't need to know anything about BarConfiguration and visa versa. I had this issue when migrating from EF 4.3 to 5.0 and I think what has changed was the discriminator database columns are not nullable in EF 5.0. I think it makes much more sense for them to be not nullable and in general it might be better to have only one discrimanotor column for each derived type as opposed to one column per type (as it was in EF 4.3)
-Stan
Getting the following error:
Schema specified is not valid. Errors:
The types in the assembly 'x, Version=1.0.0.0, Culture=neutral,
PublicKeyToken=null' cannot be loaded because the assembly contains
the EdmSchemaAttribute, and the closure of types is being loaded by
name. Loading by both name and attribute is not allowed.
What does this error mean exactly?
I'm trying to shoe-horn into my application an EF model from an existing database.
Before this application was based on CodeFirst and using the repository pattern but for the life of me I can't get this working.
Before I had:
public class BaseModelContext : DbContext
{
public DbSet<User> Users { get; set; }
public DbSet<Role> Roles { get; set; }
}
But in a EF model-first scenario (one where tables already exist in the db), I had to remove these as it didn't seem to like having a repository pattern on DbSet properties.
So I stripped these out, and the repository can then use repository on the classes already defined on the .designer.cs context class (the EF model). This has the EdmSchemaAttribute set inside the generated code.
So how do I get my repository pattern to work in the model-first scenario? What does the above error mean exactly?
EDIT
Added new code:
public class BaseModelContext : DbContext
{
// public DbSet<Location> Locations { get; set; }
public BaseModelContext(string nameOrConnection)
: base(nameOrConnection)
{
}
public BaseModelContext()
{
}
}
public class VisitoriDataContext : BaseModelContext
{
public VisitoriDataContext()
: base("visitoriDataConnection")
{
}
}
public interface IVisitoriDataContextProvider
{
VisitoriDataContext DataContext { get; }
}
public class VisitoriDataContextProvider : IVisitoriDataContextProvider
{
public VisitoriDataContext DataContext { get; private set; }
public VisitoriDataContextProvider()
{
DataContext = new VisitoriDataContext();
}
}
public class VisitoriRepository<T> : IRepository<T> where T : class
{
protected readonly IVisitoriDataContextProvider _ctx;
public VisitoriRepository(IVisitoriDataContextProvider ctx)
{
_ctx = ctx;
}
public T Get(int id)
{
return _ctx.DataContext.Set<T>().Find(id);
}
}
public interface ILocationRepo : IRepository<Location>
{
IEnumerable<Location> GetSuggestedLocationsByPrefix(string searchPrefix);
}
public class LocationRepo : VisitoriRepository<Location>, ILocationRepo
{
public LocationRepo(IVisitoriDataContextProvider ctx)
: base(ctx)
{
}
public IEnumerable<Location> GetSuggestedLocationsByPrefix(string searchPrefix)
{
return Where(l => l.name.Contains(searchPrefix)).ToList();
}
}
The error means that you cannot combine code first mapping (data annotations and fluent API) and EDMX mapping (with EntityObjects!) for entity with the same name. These two approaches are disjunctive.
The rest of your question is not clear.
Btw. building mapping from existing database is called database first not model first.
Decorate the assembly containing the GILayerModel type with [assembly: EdmSchema] attribute.
In my case, I had a class that derived from an entity (code-first class) in another assembly, and I was adding an instance of this class to the DBContext:
in DBEntities project:
public class GISLayer
{
[Key]
[DatabaseGenerated(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.Identity)]
public int GISLayerId { get; set; }
[StringLength(200)]
public string LayerName { get; set; }
public List<GISNode> Nodes { get; set; }
}
in the second assembly:
public class GISLayerModel : DBEntities.GISLayer
{
public new List<GISNodeModel> NodesModel { get; set; }
}
and the cause of error:
[WebMethod]
public void SaveGISLayers(GISLayerModel[] layers)
{
using (DBEntities.DBEntities db = new DBEntities.DBEntities())
{
foreach (var l in layers)
{
if (l.GISLayerId > 0)
{
db.GISLayers.Attach(l); //attaching a derived class
db.Entry(l).State = System.Data.EntityState.Modified;
}
else
db.GISLayers.Add(l); //adding a derived class
SaveGISNodes(l.NodesModel.ToArray(), db);
}
db.SaveChanges();
}
}
So, I used AutoMapper to copy properties of derived class to a new instance of base class:
DBEntities.GISLayer gl = AutoMapper.Mapper.Map<DBEntities.GISLayer>(l);
if (gl.GISLayerId > 0)
{
db.GISLayers.Attach(gl);
db.Entry(gl).State = System.Data.EntityState.Modified;
}
else
db.GISLayers.Add(gl);
That solved the problem.
i have this Dependency resolver
public class NinjectDependencyResolvercs : IDependencyResolver
{
private readonly IResolutionRoot resolutionRoot;
public NinjectDependencyResolvercs(IResolutionRoot kernel)
{
resolutionRoot = kernel;
}
public object GetService(Type serviceType)
{
return resolutionRoot.TryGet(serviceType);
}
public IEnumerable<object> GetServices(Type serviceType)
{
return resolutionRoot.GetAll(serviceType);
}
}
in global.asax.cs
// Ninject DI container ----------------------------------------------------------- |
public void SetupDependencyInjection()
{
// Create Ninject DI kernel
IKernel kernel = new StandardKernel();
#region Register services with Ninject DI Container
// DbContext to SqlDataContext
kernel.Bind<DbContext>()
.To<SqlDataContext>();
// IRepository to SqlRepository
kernel.Bind<IRepository>()
.To<SqlRepository>();
// IUsersServices to UsersServices
kernel.Bind<IUsersServices>()
.To<UsersServices>();
// IMessagesServices to MessagesServices
kernel.Bind<IMessagesServices>()
.To<MessagesServices>();
// IJobAdvertsServices to JobAdvertsServices
kernel.Bind<IJobAdvertsServices>()
.To<JobAdvertsServices>();
#endregion
// Tell ASP.NET MVC 3 to use Ninject DI Container
DependencyResolver.SetResolver(new NinjectDependencyResolvercs(kernel));
}
// --------------------------------------------------------------------------------- |
and class
public class SqlDataContext : DbContext
{
public DbSet<User> Users { get; set; }
public DbSet<Profile> Profiles { get; set; }
public DbSet<Role> Roles { get; set; }
public DbSet<JobAdvert> JobAdverts { get; set; }
public DbSet<Message> Messages { get; set; }
protected override void OnModelCreating(System.Data.Entity.ModelConfiguration.ModelBuilder modelBuilder)
{
modelBuilder.Entity<User>().HasMany(x => x.Roles).WithMany(x => x.Users).Map(x =>
{
x.MapLeftKey(y => y.UserId, "UserId");
x.MapRightKey(y => y.RoleId, "RoleId");
x.ToTable("UsersInRoles");
});
base.OnModelCreating(modelBuilder);
}
}
all dependecies work fine but for DbContext to SqlDataContext is problem. If use this:
public class SqlRepository
{
private DbContext dataContext;
public SqlRepository(DbContext dataContext) {
this.dataContext = dataContext;
}
public DbSet<User> Users {
get {
return dataContext.Users;
}
}
}
then
dataContext.Users
and all others properties alert this error:
'System.Data.Entity.DbContext' does not contain a definition for 'JobAdverts' and no extension method 'JobAdverts' accepting a first argument of type 'System.Data.Entity.DbContext' could be found (are you missing a using directive or an assembly reference?)
Have anyone any idea why DI doent work for Class DbContext ?
If I understand correctly, You're injecting DbContext which doesn't have those methods/properties, as they're declared in the derived type SqlDataContext.
You need to inject the SqlDataContext. If you want to use an interface, you'll need to extract an interface from SqlDataContext.
EDIT:
Ninject binds at runtime while the errors you're getting (I presume) are at compile time. You could get around this by using the dynamic key word, but that's just working AROUND the problem.
public class SqlRepository
{
private dynamic dataContext;
public SqlRepository(DbContext dataContext) {
this.dataContext = dataContext;
}
...
}
What you need to do is change the signature to use your SqlDataContext:
public class SqlRepository
{
private SqlDataContextdata Context;
public SqlRepository(SqlDataContextdata Context) {
this.dataContext = dataContext;
}
...
}
because DbContext does not contain those methods, only your SqlContext does. and your sqlcontext is bound to DbContext at runtime.