I have domain model like this
public class EntityOne
{
public int EnityOneId { get; set; }
public int EntityOnePropertyOne { get; set; }
public List<EntityTwo> EntityTwos { get; set; }
}
public class EntityTwo
{
public int EntityTwoId { get; set; }
public string EntityTwoPropertyOne { get; set; }
public int EntityThreeId { get; set; }
public int EnityOneId { get; set; }
public virtual EntityOne EntityOne { get; set; }
public virtual EntityThree EntityThree { get; set; }
}
public class EntityThree
{
public int EntityThreeId { get; set; }
public string EntityThreePropertyOne { get; set; }
}
and I have DTO like this
public class EntityDTO
{
public int EntityOnePropertyOne { get; set; }
public string EntityThreePropertyOne_ValueOne { get; set; }
public string EntityThreePropertyOne_ValueTwo { get; set; }
public string EntityThreePropertyOne_ValueThree { get; set; }
public string EntityThreePropertyOne_ValueFour { get; set; }
public string EntityThreePropertyOne_ValueFive { get; set; }
}
I want to configure mapping from DTO to DomainModel and the reverse using AutoMapper but I didnt know how to do that... any suggestion or help
I'm not sure what you're trying to accomplish here.
I get that you want to map to EntityDTO, but from what other type? I will assume you want to use EntityTwo as the source.
In that case,
EntityOnePropertyOne: Will be obtained automatically via Flattening from the source (EntityTwo) - So, no problem here.
EntityThreePropertyOne_ValueOne: This will assume you have a property called EntityThree (which you do), and within that type, a property called PropertyOne_ValueOne of type int (which you don't). Same applies for the rest.
The other way around will get trickier, since I see there will be lots of properties ignored, so you need to tell AutoMapper, that you don't want it to be concerned about all that bunch of properties in your complex type, that don't come from the DTO.
Related
I have the model with reference properties
internal class AstronomycalBody : IAstronomycalBody
{
public long Id { get; set; }
public string Name { get; set; }
public Coord Coord { get; set; }
public long Mass { get; set; }
public double Speed { get; set; }
public IAstronomycalBody CentralObject { get; set; }
}
public class Coord
{
public long X { get; set; }
public long Y { get; set; }
public long Z { get; set; }
}
I want to use mapping like this
internal class AstronomycalBodyContext : DbContext
{
public DbSet<AstronomycalBody> AstronomycalBody { get; set; }
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
optionsBuilder.UseSqlite(DbSettings.ConnectionString);
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<AstronomycalBody>().Property(p => p.Coord.X).ForSqliteHasColumnName("CoordX");
modelBuilder.Entity<AstronomycalBody>().Property(p => p.Coord.Y).ForSqliteHasColumnName("CoordY");
modelBuilder.Entity<AstronomycalBody>().Property(p => p.Coord.Z).ForSqliteHasColumnName("CoordZ");
modelBuilder.Entity<AstronomycalBody>().Property(p => p.CentralObject.Id).ForSqliteHasColumnName("CentralObjectId");
}
}
to map the model on this table:
Currently, the compiler is throwing this exception...
Your AstronomycalBody is not a valid EF entity model class.
First, EF Core does not support Complex/value types yet, so the Coord member should be expanded in place.
Second, EF does not work with interfaces, so every navigation reference / collection element type should be entity class.
With that being said, not sure how your IAstronomycalBody looks like and how you can implement it (you might need explicit implementation of some members), but the entity class should be like this:
internal class AstronomycalBody //: IAstronomycalBody
{
public long Id { get; set; }
public string Name { get; set; }
//public Coord Coord { get; set; }
public long CoordX { get; set; }
public long CoordY { get; set; }
public long CoordZ { get; set; }
public long Mass { get; set; }
public double Speed { get; set; }
public AstronomycalBody CentralObject { get; set; }
}
Now, since by convention it will generate the exact table shown, simply remove all shown lines in OnModelCreating and you are done.
i'm trying create DB using codefirst. i want to create two ForeingKey from same table. But when i set up two navigation properties of the same type, get error like :
The foreign key name 'FollowedUser' was not found on the dependent type Models.UserUserWatchListItem'. The Name value should be a comma separated list of foreign key property names.
public class UserUserWatchListItem
{
public int Id { get; set; }
[Key,ForeignKey("FollowedUser")]
public virtual User FollowedUser { get; set; }
public int FollowedUserId { get; set; }
[Key,ForeignKey("FolloweeUser")]
public int FolloweeUserId { get; set; }
public virtual User FolloweeUser { get; set; }
}
Use this :
public class UserUserWatchListItem
{
public int Id { get; set; }
public int FollowedUserId { get; set; }
public int FolloweeUserId { get; set; }
[ForeignKey("FollowedUser")]
[InverseProperty("FollowedUsers")]
public virtual User FollowedUser { get; set; }
[ForeignKey("FolloweeUser")]
[InverseProperty("FolloweeUsers")]
public virtual User FolloweeUser { get; set; }
}
public class User
{
...
[InverseProperty("FollowedUser")]
public virtual ICollection<UserUserWatchListItem> FollowedUsers { get; set; }
[InverseProperty("FolloweeUser")]
public virtual ICollection<UserUserWatchListItem> FolloweeUsers { get; set; }
}
I think, I've read everything about this error and I tried everything. Here are my models:
Main:
public class Trip
{
public int TripId { get; set; }
public string Name { get; set; }
public string ShortDescription { get; set; }
public string Country { get; set; }
public float BasicPrice { get; set; }
public virtual ICollection<ApartmentType> ApartmentType { get; set; }
public virtual ICollection<TransportMethod> TransportMethod { get; set; }
public virtual ICollection<FeedingType> FeedingType { get; set; }
}
ApartmentType:
public class TransportMethod
{
public int TransportMethodId { get; set; }
public int TripId { get; set; }
public string Name { get; set; }
public float Price { get; set; }
}
FeedingType:
public class FeedingType
{
public int FeedingTypeId { get; set; }
public int TripId { get; set; }
public string Description { get; set; }
public float Price { get; set; }
}
TransportType:
public class TransportMethod
{
public int TransportMethodId { get; set; }
public int TripId { get; set; }
public string Name { get; set; }
public float Price { get; set; }
}
When serializng the Trip entity I get a circular dependency error. Things i tried:
Disable lazy loading in DbContext.
Adding
json.SerializerSettings.PreserveReferencesHandling=Newtonsoft.Json.PreserveReferencesHandling.All; to GLobal.asax
Adding a decorator [IgnoreDataMember] to TripId in every child entity.
Mapping this entity to a ViewModel which doesn't contain the ICollection members. - This worked ok, but at some point I will want to get those lists to the client.
I really don't know what's going on. What am I missing? I really can't spot any circular dependency.
Have you tried adding the [JsonIgnore] attribute to the TripId to the children entities?
http://james.newtonking.com/projects/json/help/html/T_Newtonsoft_Json_JsonIgnoreAttribute.htm
or setting
json.SerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
I want to have a list of stands (at a trade show) and a list of exhibitors.
The list of stands is separate to the list of exhibitors - however, once registered, I want the exhibitor to be able to book a stand.
When they select/book a stand - I would like to then be able to have a list the stands in my view, and also show the associated exhibitor who has booked it.
Likewise, I would like to list in another view, the exhibitors, and also which stand they have booked.
So I'm trying to setup a one to one relationship (using EF CodeFirst).
However, when trying to add a controller for either the Stand or the Exhibitor, I get the following error:
My models are:
public class Stand
{
public int StandID { get; set; }
public string Description { get; set; }
public bool Booked { get; set; }
public int ExhibitorID { get; set; }
public virtual Exhibitor Exhibitor { get; set; }
}
public class Exhibitor
{
public int ExhibitorID { get; set; }
public string Company { get; set; }
public int StandID { get; set; }
public virtual Stand Stand { get; set; }
}
I'm certain it's something to do with the "Virtual" part of the models.
Can anyone please help point out what should be updated, to allow the connection?
Thank you,
Mark
EF doesn't know which entity is the principal (parent) and which is the dependent (child). You need to declare a foreign key on the item that entity that should come first. You can do this with an annotation or a fluent mapping.
Annotation
Add the following namespace:
using System.ComponentModel.DataAnnotations.Schema;
Annotate your Stand class with the following annotation:
public class Stand
{
[ForeignKey("Exhibitor")]
public int StandID { get; set; }
public string Description { get; set; }
public bool Booked { get; set; }
public int ExhibitorID { get; set; }
public virtual Exhibitor Exhibitor { get; set; }
}
Fluent Mapping
Override your OnModelCreating method in your DbContext class to include:
modelBuilder.Entity<Stand>()
.HasOptional(s => s.Exhibitor)
.WithRequired(e => e.Stand);
The model you have created is not possible to work with relational databases. The Stand needs an ExibitorId while Exibitor need a StandId. The cyclic relationship does not allow you to insert any rows to either tables.
Assuming an Exibitor may have more than one Stand and converting the relationship to one-to-many is one option.
public class Stand
{
public int StandID { get; set; }
public string Description { get; set; }
public bool Booked { get; set; }
public int? ExhibitorID { get; set; }
public virtual Exhibitor Exhibitor { get; set; }
}
public class Exhibitor
{
public int ExhibitorID { get; set; }
public string Company { get; set; }
public virtual ICollection<Stand> Stands { get; set; }
}
Or you can use shared primary key mapping to make the relationship one-to-one. Where Stand is the principal entity. The Exibitor will use the StandID as its PK.
public class Stand
{
public int StandID { get; set; }
public string Description { get; set; }
public bool Booked { get; set; }
public virtual Exhibitor Exhibitor { get; set; }
}
public class Exhibitor
{
public int ExhibitorID { get; set; }
public string Company { get; set; }
public virtual Stand Stand { get; set; }
}
Using the Fluent API to configure the relationship.
modelBuilder.Entity<Exibitor>().HasRequired(e => e.Stand)
.WithOptional(s => s.Exibitor);
I have the following model:
public class Member
{
public int Id { get; set; }
public string Username { get; set; }
public int MainEmailId { get; set; }
public virtual Email MainEmail { get; set; }
public virtual ICollection<Email> MemberEmails { get; set; }
}
public partial class Email
{
public Int32 Id { get; set; }
public String Email { get; set; }
public int MemberId { get; set; }
public virtual Member Member { get; set; }
}
As you can see I wish to create a:
one-to-one relation from the Member to MemberEmail (the main email address)
one-to-many relation from Member to MemberEmail
I know how to do this with Code First Fluent API. However I need to do it with DataAnnotations only. Is this possible?
Thanks a lot.