I'm starting to use AutoMapper for my project.
For this I want to do the following 'one-to-many' mapping:
Source:
public class Team
{
int Id { get; set; }
string TeamName { get; set; }
List<Person> Member { get; set; }
}
public class Person
{
int Id { get; set; }
string Name { get; set; }
}
Destination:
public class TeamDetailsViewModel
{
int Id { get; set; }
string TeamName { get; set; }
List<int> MemberIds { get; set; }
}
How to proceed with AutoMapper? Is this possible?
Thanks a lot in advance.
This map should work for you:
CreateMap<Team, TeamDetailsViewModel>()
.ForMember(d=>d.MemberIds, o=>o.MapFrom(s=>s.Member.Select(m=>m.Id)));
FYI...If you are getting the Team from a db, make sure you are eager loading the Member list.
Related
I have the following main class:
public class ResearchOutcome
{
public ResearchOutcomeCategory ResearchOutcomeCategory { get; set; }
public string? UniqueIdentifier { get; set; }
}
And the category class is:
public class ResearchOutcomeCategory
{
public int Id { get; set; }
public string Name { get; set; }
public string? Description { get; set; }
}
The View models for above classes are:
public class ResearchOutcomeDetailVm : IMapFrom<ResearchOutcome>
{
public int Id { get; set; }
public virtual ResearchOutcomeCategoryDetailVm ResearchOutcomeCategory { get; set; }
}
public class ResearchOutcomeCategoryDetailVm : IMapFrom<ResearchOutcomeCategory>
{
public int Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
}
Now, I have used the following mapping profile:
// First this one
profile.CreateMap<ResearchOutcomeCategory, ResearchOutcomeCategoryDetailVm>();
profile.CreateMap<ResearchOutcome, ResearchOutcomeDetailVm>();
//Then I tried this one
profile.CreateMap<ResearchOutcome, ResearchOutcomeDetailVm>()
.ForMember(o => o.ResearchOutcomeCategory,
cat => cat.MapFrom( o => o.ResearchOutcomeCategory));
But the ResearchOutcomeCategory is always null. Any help would be appreciated.
After digging more, I identified that I was not "Including" the relevant item in the query, hence, the view model was always empty. Pretty dumb on my part :D
Regarding the mapping, if the properties (even complex ones) have the same names, then the mapper will map them automatically. So simply this line worked
profile.CreateMap<ResearchOutcomeCategory, ResearchOutcomeCategoryDetailVm>();
Hope it helps someone
I model three entities in the auto industry as following:
public class Manufacturer
{
public int Id { get; set; }
public string Name { get; set; }
public ICollection<Model> Models { get; set; }
public ACManufacturer()
{
AutoCareModels = new List<ACModel>();
}
}
public class Model
{
public int Id { get; set; }
public string Name { get; set; }
public int NumberOfSeats { get; set; }
public Manufacturer Manufacturer { get; set; }
public ICollection<ManufacturedYear> ManufacturedYears { get; set; }
public Model()
{
ManufacturedYears = new List<ManufacturedYear>();
}
}
public class ManufacturedYear
{
public int Id { get; set; }
public int ProductionYear { get; set; }
public Model Model { get; set; }
}
Please tell me how to choose aggregate root or the differente way to model three entities
Thank you every much
Answer depends on what you do with these models. What is your app doing? If 10 users are updating data in this app - how can they divide their work? What are transaction boundaries?
If those 10 users are usually working with 10 different models, your screens are organized around models, then Model is your aggregate root.
How to relate the data in following scenario:
Ninja -> NinjaItem -> ItemList
So that NinjaItem-table would contain data of the items belonging to the Ninja? ItemList-table should contain only item-name and id.
I have the following that relates the Ninja to NinjaItem but I cannot figure out how to relate also NinjaItem to ItemList.
public class Ninja
{
public int ID { get; set; }
public string Name { get; set; }
public virtual List<NinjaItem> NinjaItem { get; set; }
}
public class NinjaItem
{
public int ID { get; set; }
public int NinjaID { get; set; }
public int ItemListID { get; set; }
public virtual List<ItemList> ItemList{ get; set; }
}
public class ItemList
{
public int Id { get; set; }
public string Name { get; set; }
}
Moved solution from question to answer:
SOLUTION:
I only needed two classes Ninja and ItemList and Entity Framework creates the third table linking items to ninjas.
public class Ninja
{
public Ninja ()
{
this.ItemLists = new HashSet<ItemList>();
}
public int NinjaId { get; set; }
public string Name { get; set; }
public virtual ICollection<ItemList> ItemLists { get; set; }
}
public class ItemList
{
public ItemList ()
{
this.Ninjas = new HashSet<Ninja>();
}
public int ItemListId { get; set; }
public string ItemName { get; set; }
public virtual ICollection<Ninja> Ninjas { get; set; }
}
I am trying to implement DbContext for couple of tables called 'Employee' and 'Department'
Relationship between Employee and Department is many to one. i.e. department can have many employees.
Below are the EntityFramework classes I designed ( CodeFirst approach )
[Table("Employee")]
public class Employee
{
[DatabaseGenerated(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
[Column("Name")]
public string Name { get; set; }
[Column("Department_ID")]
public int Department_ID { get; set; }
public virtual Department Department { get; set; }
}
[Table("Department")]
public class Department
{
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int ID { get; set; }
[Column("Name")]
public string Name { get; set; }
public virtual ICollection<Employee> Employees { get; set; }
}
While adding Employee record I am getting below exception
"Invalid column name 'Department_ID1'."
I am not sure why EF is referring to Department_ID1. Do I need to add configuration in OnModelCreating method of DbContext?
I am using EF version 6.1.1
I've also gotten this problem in my EF one-many deals where the one has a List of the many property and my mapping didn't specify that property. For example take:
public class Notification
{
public long ID { get; set; }
public IList<NotificationRecipient> Recipients { get; set; }
}
then
public class NotificationRecipient
{
public long ID { get; set; }
public long NotificationID { get; set; }
public Notification Notification { get; set; }
}
Then in my mapping, the way that caused the Exception (the incorrect way):
builder.HasOne(x => x.Notification).WithMany()
.HasForeignKey(x => x.NotificationID);
What fixed it (the correct way) was specifying the WithMany property:
builder.HasOne(x => x.Notification).WithMany(x => x.Recipients)
.HasForeignKey(x => x.NotificationID);
Hi After spending some time I could fix this problem by using ForeignKey attribute on public virtual Department Department { get; set; } property of Employee class.
Please see below code.
[Table("Employee")]
public class Employee
{
[DatabaseGenerated(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
[Column("Name")]
public string Name { get; set; }
[Column("Department_ID")]
public int Department_ID { get; set; }
[ForeignKey("Department_ID")]
public virtual Department Department { get; set; }
}
This fixed my problem. Are there any other solution to fix this? Using fluent API?
For me, the issue was resolved by removing a (duplicate?) virtual property.
Using the OP's example:
public class Employee
{
public int Id { get; set; }
public string Name { get; set; }
public int Department_ID { get; set; }
public virtual Department Department { get; set; }
}
public class Department
{
public int ID { get; set; }
public string Name { get; set; }
public virtual ICollection<Employee> Employees { get; set; }
}
Turns into:
public class Employee
{
public int Id { get; set; }
public string Name { get; set; }
public int Department_ID { get; set; }
}
public class Department
{
public int ID { get; set; }
public string Name { get; set; }
public virtual ICollection<Employee> Employees { get; set; }
}
In my case I added a virtual property on top of the auto generated property
I fixed it by adding the NotMapped attribute to my property, or you could configure with fluent api
public partial class Control
{
[NotMapped]
public virtual ICollection<Control> Children { get => this.InverseParent; set => this.InverseParent = value; }
}
I had the same error, my issue was the FK was a long but I had it as an int in the model. EF generated a new column because it didn't match types on the FK so it assumed they weren't the same and went ahead with making another one but putting 1 at the end because there was already one with the proper name. Making sure the types matched resolved the issue for me.
This can be fixed simply by putting [NotMapped] annotation on your virtual properties.
public class Employee
{
[ForeignKey("Department")]
public int Department_ID
[NotMapped]
public virtual Department Department { get; set; }
}
And in you modelBuilder:
modelBuilder.Entity<Employee>(entity =>
{
entity.HasOne(e => e.Department);
});
Just flip this around if you want to call by Department.
We use the [NotMapped] annotation so that EF Core will disregard it when looking at your database.
I have a problem with devising a many to many relationship in code first. EF is creating the Junction table and associating the Fk's as I would expect, however when i try to access the User's MailingList collection, there are no entries.
I've implemented test data on Initialise via Seeding, the data is al present in the database.
I think the problem lies with the constructors for Users and MailingLists, but I'm uncertain. I want to be able to navigate the navigational property of User.MailingLists.
var user = db.Users.Find(1);
Console.WriteLine("{0}", user.EmailAddress); //This is Fine
Console.WriteLine("{0}", user.Address.PostCode); /This is Fine
foreach (MailingList ml in user.MailingLists) // this is 0
{
Console.WriteLine("{0}", ml.Name);
}
My model is below:-
public class User : IEntityBase
{
public User()
{
MailingLists = new List<MailingList>();
}
public int Id { get; set; }
public string Forename { get; set; }
public string Surname { get; set; }
public string EmailAddress { get; set; }
public DateTime? DateLastUpdated { get; set; }
public DateTime DateCreated { get; set; }
public bool IsDeleted { get; set; }
public virtual Address Address { get; set; }
public ICollection<MailingList> MailingLists { get; set; }
}
public class MailingList : IEntityBase
{
public MailingList()
{
Users = new List<User>();
}
public int Id { get; set; }
public string Name { get; set; }
public DateTime? DateLastUpdated { get; set; }
public DateTime DateCreated { get; set; }
public bool IsDeleted { get; set; }
public ICollection<User> Users { get; set; }
}
public class Address : IEntityBase
{
public int Id { get; set; }
public string AddressLine1 { get; set; }
public string AddressLine2 { get; set; }
public string AddressLine3 { get; set; }
public string City { get; set; }
public string County { get; set; }
public string PostCode { get; set; }
public DateTime? DateLastUpdated { get; set; }
public DateTime DateCreated { get; set; }
public bool IsDeleted { get; set; }
}
Any suggestions welcome.
You are neither eager loading the MailingList entries with the query, nor fulfulling the requirements for a lazy loading proxy so there is no way EF can populate the collection.
To allow lazy loading, change the MailingList property to be virtual to allow the EF proxy to override it.
To use eager loading, use Include() (an extension method in System.Data.Entity) in the query to specify that the MailingList should be loaded.