I have two to be related entities as below :
public class VehicleExtraEntity
{
public int Id { get; set; }
public Guid NameKey { get; set; }
public virtual ICollection<WordEntity> WordsOfName { get; set; }
}
And the other entity :
public class WordEntity
{
public int Id { get; set; }
public string Content { get; set; }
public Guid Key { get; set; }
}
My purpose is write multi language supported db tables. For example ;
WordEntity1 : {Id=1, Content="Child Seat", Key="abcdef-12456"}
WordEntity2 : {Id=2, Content="Çocuk Koltuğu", Key="abcdef-12456"} --> Same Key
VehicleExtraEntity1 : {Id=1, NameKey = "abcdef-123456"}
I have tried fluent api but that support only relationships with navigation property. And it wants to me use many to many relationship. But I want resolve my problem as I wrote as above.
Related
I want to add two properties from the city model:
after migration this error shows up:
Unable to determine the relationship represented by navigation
'City.Orders' of type 'ICollection'. Either manually configure
the relationship, or ignore this property using the '[NotMapped]'
attribute or by using 'EntityTypeBuilder.Ignore' in 'OnModelCreating'.
here is my code :
public class Order
{
public virtual City FromCity { get; set; }
public virtual City ToCity { get; set; }
}
public class City
{
public int Id { get; set; }
public string Name { get; set; }
public virtual ICollection<Order> Orders { get; set; }
}
I suppose your model is more complicated than just FromCity and ToCity because I don't think it's a good idea to store such information in a different table. Yet, You can use inheritance in this case.
The table-per-hierarchy (TPH) pattern is used by default to map the inheritance in EF. TPH stores the data for all types in the hierarchy in a single table.
However, for your scenario, you can have a base class that holds all related attributes.
public class CityBase
{
public int Id { get; set; }
public string Name { get; set; } = string.Empty;
}
Then suppose you need two entities as per your scenario:
public class FromCity : CityBase
{
public virtual ICollection<Order> Orders { get; set; } = null!;
}
public class ToCity : CityBase
{
public virtual ICollection<Order> Orders { get; set; } = null!;
}
And the order entity:
public class Order
{
public int Id { get; set; }
public string OrderTitle { get; set; } = string.Empty;
public virtual FromCity FromCity { get; set; } = null!;
public virtual ToCity ToCity { get; set; } = null!;
}
This approach can solve your problem with a One-to-Many relationship between Orders and FromCity, ToCity as per below diagram:
I have implemented following generic model as base model and two models derived from it and i need one to many relationship. I have used fluent api to create the relationships but i get the error mentioned in the title.
Would you please see if you find any thing wrong in my code.
public abstract class ModelBase<T> : BaseEntity, IModelBase<T>
{
public virtual T Id { get; set; }
}
[Table("VehicleModel", Schema = "Tracker")]
public class VehicleModelModel : ModelBase<int>
{
public string Company { get; set; }
public string ModelName { get; set; }
public byte LiPerKM { get; set; }
public virtual ICollection<VehicleModel> Vehicles { get; set; }
[Table("Vehicle", Schema = "Tracker")]
public class VehicleModel : ModelBase<Guid>
{
public string VehicleName { get; set; }
public string LicensePlate { get; set; }
public int VehicleModelId { get; set; }
public virtual VehicleModelModel Model { get; set; }
public virtual TrackerModel Tracker { get; set; }
[Required]
public virtual DriverModel Driver { get; set; }
modelBuilder.Entity<VehicleModel>()
.HasRequired<VehicleModelModel>(s => s.Model)
.WithMany(s => s.Vehicles)
.HasForeignKey(s => s.VehicleModelId);
Here I get this error:
entity types 'VehicleModelModel' and 'VehicleModel' cannot share table 'VehicleModels' because they are not in the same type hierarchy or do not have a valid one to one foreign key relationship with matching primary keys between them.
I am trying to create a many-to-many relationship between ApplicationUser and Reserve.
public class ApplicationUser : IdentityUser
{
public ApplicationUser()
{
this.Reserves = new HashSet<Reserve>();
}
public bool IsProfessional { get; set; }
public virtual ICollection<Reserve> Reserves { get; set; }
}
public class Reserve
{
public Reserve()
{
this.Usuarios = new HashSet<ApplicationUser>();
}
public int ID { get; set; }
public string Begin { get; set; }
public string End { get; set; }
public string Date { get; set; }
public string Status { get; set; } //free , reserved, confirmed, canceled
public DateTime LastUpdate { get; set; }
public virtual ICollection<ApplicationUser> Usuarios { get; set; }
}
But I cant add the migration
PM> Add-Migration user-reserve-relationship
Unable to determine the relationship represented by navigation property 'ApplicationUser.Reserves' of type 'ICollection<Reserve>'. Either manually configure the relationship, or ignore this property from the model.
Anyway, the same relationship works well to others entities but not ApplicationUser.
Can I use ApplicationUser many-to-many?
I found the follow in ef core :
Many-to-many relationships without an entity class to represent the join table are not yet supported.
So my question is closed.
I have 2 models:
public class TransactionHistory : IDbEntity {
[Key]
public int ID { get; set; }
public ItemHistory ItemHistory { get; set; }
}
public class ItemHistory : IDbEntity {
[Key]
public int ID { get; set; }
public int TransactionHistoryID { get; set; }
public TransactionHistory TransactionHistory { get; set; }
}
There's a one to one relationship between TransactionHistory and ItemHistory, ItemHistory MUST have a TransactionHistory but TransactionHistory may or may not have an ItemHistory.
I want to be able to do this in code:
var test = db.ItemHistory.Include(x => x.TransactionHistory).ToList();
As well as:
var test2 = db.TransactionHistory.Include(x => x.ItemHistory).ToList();
But I only want a single FK on the ItemHistory table.
With the code I've listed I get this error:
Unable to determine the principal end of an association between the types 'InventoryLibrary.DomainModels.TransactionHistory' and 'InventoryLibrary.DomainModels.ItemHistory'. The principal end of this association must be explicitly configured using either the relationship fluent API or data annotations.
How is this achieved in Entity Framework code first data annotations?
Firstly, you have to mark foreign keys by virtual keyword to enable overrides.
public class TransactionHistory : IDbEntity
{
[Key]
public int ID { get; set; }
public virtual ItemHistory ItemHistory { get; set; }
}
public class ItemHistory : IDbEntity
{
[Key]
public int ID { get; set; }
public int TransactionHistoryID { get; set; }
[Required]
public virtual TransactionHistory TransactionHistory { get; set; }
}
If HistoryItem must have Transaction History, add DataAnnotation [Required], which makes it non-nullable.
Finally, wonder, if you want to have one-to-one relationship. I imagine you'd like to have many transaction history entries. Am I right? If not - let me know.
To create one-to-many relationship, use IEnumerable<> type.
I have two tables (Table A, Table B) joined with a join table (TableAB) with 3 payload columns. By Payload I mean columns apart from Id, TableAId, and TableBId.
I can insert into all tables successfully, but I need to insert data into one of the payload columns on Insert. I'm using EF 4.3, Fluent API. Can anyone help? Thanks in advance.
public class Organisation : EntityBase<int>, IAggregateRoot
{
public string Name { get; set; }
public string Url { get; set; }
public int CountryId { get; set; }
public int? OwnershipTypeId { get; set; }
public int OrganisationStatusId { get; set; }
public virtual ICollection<Feature> Features { get; set; }
public virtual ICollection<OrganisationType> OrganisationTypes { get; set; }
public virtual ICollection<PricePlan> PricePlans { get; set; }
public virtual ICollection<User> Users { get; set; }
}
public class User: EntityBase<Guid>, IAggregateRoot
{
public string FirstName { get; set; }
public string LastName { get; set; }
public string JobTitle { get; set; }
public int? PhoneCallingCodeId { get; set; }
public int? PhoneAreaCode{ get; set; }
public string PhoneLocal { get; set; }
public int? MobileCallingCodeId { get; set; }
public int? MobileAreaCode { get; set; }
public string MobileLocal { get; set; }
public virtual ICollection<Organisation.Organisation> Organisations { get; set; }
}
public class OrganisationUser : EntityBase<int>, IAggregateRoot
{
public DateTime StartDate { get; set; }
public DateTime? EndDate { get; set; }
public int OrganisationRoleId {get; set;}//Foreign Key - have tried leaving it out, tried it as public virtual Organisation Organisation {get;set;
public bool IsApproved { get; set; }
}
public class SDContext : DbContext
{
public ObjectContext Core
{
get
{
return (this as IObjectContextAdapter).ObjectContext;
}
}
public IDbSet<User> User { get; set; }
public IDbSet<Organisation> Organisation { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
modelBuilder.Entity<Organisation>().HasMany(u => u.Users).WithMany(o => o.Organisations).Map(m =>
{
m.MapLeftKey("OrganisationId");
m.MapRightKey("UserId");
m.ToTable("OrganisationUser");
});
//I have tried specifically defining the foreign key in fluent, but I really need to understand how I can add the payload properties once I access and edit them.
Your mapping is not correct for your purpose. If you want to treat OrganisationUser as an intermediate entity between Organisation and User you must create relationships between Organisation and OrganisationUser and between User and OrganisationUser, not directly between Organisation and User.
Because of the intermediate entity which contains its own scalar properties you cannot create a many-to-many mapping. EF does not support many-to-many relationships with "payload". You need two one-to-many relationships:
public class Organisation : EntityBase<int>, IAggregateRoot
{
// ...
// this replaces the Users collection
public virtual ICollection<OrganisationUser> OrganisationUsers { get; set; }
}
public class User : EntityBase<Guid>, IAggregateRoot
{
// ...
// this replaces the Organisations collection
public virtual ICollection<OrganisationUser> OrganisationUsers { get; set; }
}
public class OrganisationUser : EntityBase<int>, IAggregateRoot
{
public int OrganisationId { get; set; }
public Organisation Organisation { get; set; }
public Guid UserId { get; set; }
public User User { get; set; }
// ... "payload" properties ...
}
In Fluent API you must replace the many-to-many mapping by the following:
modelBuilder.Entity<Organisation>()
.HasMany(o => o.OrganisationUsers)
.WithRequired(ou => ou.Organisation)
.HasForeignKey(ou => ou.OrganisationId);
modelBuilder.Entity<User>()
.HasMany(u => u.OrganisationUsers)
.WithRequired(ou => ou.User)
.HasForeignKey(ou => ou.UserId);
Your derived DbContext may also contain a separate set for the OrganisationUser entity:
public IDbSet<OrganisationUser> OrganisationUsers { get; set; }
It's obvious now how you write something into the intermediate table:
var newOrganisationUser = new OrganisastionUser
{
OrganisationId = 5,
UserId = 8,
SomePayLoadProperty = someValue,
// ...
};
context.OrganisastionUsers.Add(newOrganisastionUser);
context.SaveChanges();
If you want to make sure that each pair of OrganisationId and UserId can only exist once in the link table, it would be better to make a composite primary key of those two columns to ensure uniqueness in the database instead of using a separate Id. In Fluent API it would be:
modelBuilder.Entity<OrganisationUser>()
.HasKey(ou => new { ou.OrganisationId, ou.UserId });
More details about such a type of model and how to work with it is here:
Create code first, many to many, with additional fields in association table