The user(AskedUser) can have many questions asked by other users(Asker).
Users(Asker) can ask questions to other users(AskedUser).
So the QuestionModel should have foreign key to asked user id and foreign key to user who asked the question.
Do I constructed my models to what I want to achieve? How to configure this using fluent api cause this is not achievable using data annotations only.
public class ApplicationUser : IdentityUser<long>
{
public string FirstName { get; set; }
public string LastName { get; set; }
public string City { get; set; }
public string Country { get; set; }
public DateTime BirthDate { get; set; }
public ICollection<QuestionModel> AskedQuestions { get; set; }
}
public class QuestionModel
{
public int Id { get; set; }
public string Content { get; set; }
public bool IsAnswered { get; set; }
public long AskerId { get; set; }
public ApplicationUser Asker { get; set; }
public long AskedUserId { get; set; }
public ApplicationUser AskedUser { get; set; }
}
This is I've tried so far
builder.Entity<ApplicationUser>()
.HasMany(user => user.AskedQuestions)
.WithOne(q => q.AskedUser)
.HasForeignKey(user => user.AskedUserId)
.HasConstraintName("ForeignKey_User_AskedQuestion")
.HasForeignKey(user => user.AskerId)
.HasConstraintName("ForeignKey_Asker_QuestionAsked")
.IsRequired(true);
You can do it on QuestionModel
//Asker relation
builder.Entity<QuestionModel>()
.HasOne(q=> q.Asker)
.Withmany(u => u.AskedQuestions)
.HasForeignKey(q=> q.AskerId)
.HasConstraintName("ForeignKey_Asker_QuestionAsked")
.IsRequired(true);
//Asked relation
builder.Entity<QuestionModel>()
.HasOne(q=> q.AskedUser)
.Withmany()
.HasForeignKey(q=> q.AskeduserId)
.HasConstraintName("ForeignKey_User_AskedQuestion")
.IsRequired(true);
I use Fluent API on dependant model instead of the root element.
Related
I'm trying to create a many to many relation in the Fluent API with Ef Core 6 but i am having trouble understanding how to do so.
I've looked around here in stackoverflow but couldn't understand this relation and how to reproduce it in my code.
I have a table in my SQL database called People:
People.cs:
public class People : PeopleBase
{
public People()
{
RegistrationList = new HashSet<Registration>();
}
public virtual ICollection<Registration> RegistrationList { get; set; }
public virtual User User { get; set; }
public virtual ActivityGroup ActivityGroup { get; set; }
}
PeopleBase.cs:
public abstract class PeopleBase: ModelBase
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public Guid PeopleId { get; set; }
public Guid? UserId { get; set; }
public Guid? ActivityGroupId { get; set; }
public string Code { get; set; }
public string Name { get; set; }
public string Surname { get; set; }
public PeopleActiveType Active { get; set; }
}
And then i have another table called ActivityGroup:
ActivityGroup.cs:
public class ActivityGroup : ActivityGroupBase
{
public ActivityGroup()
{
PeopleList = new HashSet<People>();
ActivityList = new HashSet<Activity>();
}
public ICollection<People> PeopleList { get; set; }
public ICollection<Activity> ActivityList { get; set; }
}
ActivityGroupBase.cs:
public abstract class ActivityGroupBase : ModelBase
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public Guid ActivityGroupId { get; set; }
[Required]
[StringLength(20)]
public string Name { get; set; }
public StatusRecord Status { get; set; }
}
How would i do the mapping in the modelBuilder given that:
ActivityGroupId is the foreing key in the People database, pointing to the other table
One PeopleId can have multiple (many) ActivityGroupId
One ActivityGroupId can be assigned to multiple people.
What i've done so far:
modelBuilder.Entity<People>()
.HasOne(x => x.ActivityGroup)
.WithMany(x => x.PeopleList)
.HasForeignKey(x => x.ActivityGroupId);
Wouldn't i have to do this instead?
modelBuilder.Entity<People>()
.Hasmany(x => x.ActivityGroupList) //this is a ICollection<ActivityGroup> inside People class
.WithMany(x => x.PeopleList)
.HasForeignKey(x => x.ActivityGroupId); // this is not recognized by Ef Core
Can anyone help me please?
There are two main approaches for many-to-many relationships - with implicit junction table:
public class People : PeopleBase
{
// ...
public virtual List<Activity> Activities { get; set; }
}
public class Activity // : ...
{
// ...
public virtual List<People> PeopleList { get; set; }
}
modelBuilder.Entity<People>()
.HasMany(x => x.Activities)
.WithMany(x => x.PeopleList);
Or with explicit one:
public class People
{
// ...
public ICollection<PeopleActivity> PeopleActivities { get; set; }
}
public class Activity
{
// ...
public virtual ICollection<PeopleActivity> PeopleActivities { get; set; }
}
public class PeopleActivity
{
public Guid ActivityId { get; set; }
public Guid PeopleId { get; set; }
public Activity Activity { get; set; }
public People People { get; set; }
}
modelBuilder.Entity<PeopleActivity>()
.HasOne(pt => pt.People)
.WithMany(t => t.PeopleActivities)
.HasForeignKey(pt => pt.PeopleId);
Also maybe it worth changing entity name from People to Person (you can change table name with .ToTable("People") call)?
In project I can have one User that can have many UserActivites. In my models I've set up their relationship as follows:
public class User
{
public int Id { get; set; }
public string UserName { get; set; }
public string FirstName { get; set; }
public string Surname { get; set; }
public string Email { get; set; }
//relationship mapping example
// delete these attributes and you'll cause a self referenceing loop error
[JsonIgnore]
[IgnoreDataMember]
public List<UserActivity> Activities { get; set; }
}
public class UserActivity
{
public int Id { get; set; }
public string UserName { get; set; }
public string Email { get; set; }
public string Project { get; set; }
public DateTime EntryDate { get; set; }
// relationship mapping
public User User { get; set; }
}
And in my repository class, I'm getting all my user activities this way:
public async Task<IEnumerable<UserActivity>> GetAll()
{
var result = await _context.UserActivities.Include(activity => activity.User).OrderByDescending(x => x.EntryDate).ToListAsync();
return result;
}
However, when I run my project, the User property of UserActivities is null. So I checked the Microsoft docs on EF Core relationships and updated my OnModelCreating method inside of my context to also do the mapping as follows:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<UserActivity>().ToTable("UserActivities").Property(x => x.Id).ValueGeneratedOnAdd();
modelBuilder.Entity<UserActivity>().ToTable("UserActivities").HasOne(x => x.User).WithMany();
modelBuilder.Entity<User>().ToTable("Users").Property(x => x.Id).ValueGeneratedOnAdd();
base.OnModelCreating(modelBuilder);
}
However, when I run the project again, my User property still isn't populated. I know this isn't a data issue as I have data inside of my User table and display that on a separate page.
I'm not sure what I'm doing wrong/missing with this. So any help would be appreciated
Try this code:
Your tables:
public partial class User
{
public User()
{
UserActivities = new HashSet<UserActivity>();
}
[Key]
public int Id { get; set; }
[Required]
public string UserName { get; set; }
[Required]
public string FirstName { get; set; }
[Required]
public string LastName { get; set; }
public string Email { get; set; }
[InverseProperty(nameof(UserActivity.User))]
public virtual ICollection<UserActivity> UserActivities { get; set; }
}
public partial class UserActivity
{
[Key]
public int Id { get; set; }
public int UserId { get; set; }
public string Project { get; set; }
public DateTime EntryDate { get; set; }
[ForeignKey(nameof(UserId))]
[InverseProperty("UserActivity")]
public virtual User User { get; set; }
}
dbcontext:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<UserActivity>(entity =>
{
entity.HasOne(d => d.User)
.WithMany(p => p.UserActivities)
.HasForeignKey(d => d.UserId)
.OnDelete(DeleteBehavior.ClientSetNull)
.HasConstraintName("FK_UserActivity_User");
});
OnModelCreatingPartial(modelBuilder);
}
In my regular .NET Framework application, I was using EF 6.x and was also using some Inheritance, specifically:
PurchaseOrder.cs and SaleOrder.cs both inherit from Order.cs
And in the OnModelCreating() on my context class inheriting from IdentityDbContext, I was doing:
modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
This used to work, but now I am moving my application to .NET Core 2.0 and I am using EF Core. What achieves the same thing in EF Core? Because right now I am getting the error:
System.Data.SqlClient.SqlException (0x80131904): Introducing FOREIGN KEY constraint 'FK_Order_Business_CustomerId' on table 'Order' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.
UPDATE
Here's the code after Ahmar's answer. In my context class, I have:
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
builder.HasDefaultSchema("PD");
builder.Entity<Customer>()
.HasMany(c => c.SaleOrders)
.WithOne(e => e.Customer)
.OnDelete(DeleteBehavior.SetNull);
builder.Entity<Supplier>()
.HasMany(po => po.PurchaseOrders)
.WithOne(e => e.Supplier)
.OnDelete(DeleteBehavior.SetNull);
builder.Entity<PurchaseOrder>()
.HasMany(li => li.LineItems)
.WithOne(po => po.PurchaseOrder)
.OnDelete(DeleteBehavior.SetNull);
builder.Entity<SaleOrder>()
.HasMany(li => li.LineItems)
.WithOne(po => po.SaleOrder)
.OnDelete(DeleteBehavior.SetNull);
}
And as far the Entities, they are:
public abstract class Business : IEntity
{
protected Business()
{
CreatedOn = DateTime.UtcNow;
}
public int Id { get; set; }
public string Name { get; set; }
public string TaxNumber { get; set; }
public string Description { get; set; }
public string Phone { get; set; }
public string Website { get; set; }
public string Email { get; set; }
public bool IsDeleted { get; set; }
public DateTime CreatedOn { get; set; }
public DateTime? ModifiedOn { get; set; }
public ICollection<Address> Addresses { get; set; } = new List<Address>();
public ICollection<Contact> Contacts { get; set; } = new List<Contact>();
}
[Table("Customers")]
public class Customer : Business
{
public decimal AllowedCredit { get; set; }
public decimal CreditUsed { get; set; }
public int NumberOfDaysAllowedToBeOnMaxedOutCredit { get; set; }
public ICollection<SaleOrder> SaleOrders { get; set; }
}
[Table("Suppliers")]
public class Supplier : Business
{
public ICollection<PurchaseOrder> PurchaseOrders { get; set; }
}
public abstract class Order : IEntity
{
protected Order()
{
Date = DateTime.UtcNow;
CreatedOn = DateTime.UtcNow;
}
public int Id { get; set; }
public DateTime Date { get; set; }
public decimal ShippingCost { get; set; }
public Currency ShippingCurrency { get; set; }
public decimal ShippingConversionRate { get; set; }
public bool IsDeleted { get; set; }
public DateTime CreatedOn { get; set; }
public DateTime? ModifiedOn { get; set; }
public ICollection<Invoice> Invoices { get; set; }
public ICollection<Note> Notes { get; set; }
}
[Table("PurchaseOrders")]
public class PurchaseOrder : Order
{
public int SupplierOrderNumber { get; set; }
public PurchaseOrderStatus Status { get; set; }
public decimal Vat { get; set; }
public decimal ImportDuty { get; set; }
public int SupplierId { get; set; }
public Supplier Supplier { get; set; }
public ICollection<PurchaseOrderLineItem> LineItems { get; set; }
}
[Table("SaleOrders")]
public class SaleOrder : Order
{
public decimal AmountToBePaidOnCredit { get; set; }
public SaleOrderStatus Status { get; set; }
public ICollection<SaleOrderLineItem> LineItems { get; set; }
public int CustomerId { get; set; }
public Customer Customer { get; set; }
}
So after doing what Ahmar suggested, I still get the same error when I do update-database.
You need to configure cascade delete behavior on each entity in .Net Core EF.
The Entity Framework Core Fluent API OnDelete method is used to specify the action which should take place on a dependent entity in a relationship when the principal is deleted.
The OnDelete method takes a DeleteBehavior enum as a parameter:
Cascade - dependents should be deleted
Restrict - dependents are
unaffected
SetNull - the foreign key values in dependent rows should
update to NULL
Example:
public class Company
{
public int Id { get; set; }
public string Name { get; set; }
public ICollection<Employee> Employees { get; set; }
}
public class Employee
{
public int Id { get; set; }
public string Name { get; set; }
public int? CompanyId { get; set; }
public Company Company { get; set; }
}
protected override void OnModelCreating(Modelbuilder modelBuilder)
{
modelBuilder.Entity<Company>()
.HasMany(c => c.Employees)
.WithOne(e => e.Company).
.OnDelete(DeleteBehavior.SetNull);
}
When deleting the Company, it will set CompanyId property in Employee table to null.
Get more detail at Configuring One To Many Relationships
PS. Please make sure your all referencing properties should be null able so, EF Core can set them null on delete. like CompanyId in about example.
I have more of a theoretical question. I have three Models. Employee, Commission and Position. Currently I created a ManyToMany relationship database EmployeeCommission (an Employee has many Commissions and Commissions have many Employees) but I also need to add Position to the relationship which would make that Commissions have many Employees that can have many Positions and so on. (Same employee can have different positions in different commissions).
How do I go about this? I know that ManyToMany relationship can only be between to models, so how do I create a ManyToMany database between three models?
Here's my Models, but I don't think you'll need them, but just for general information.
public class Employee
{
public int Id { get; set; }
public string Name { get; set; }
public string Surname { get; set; }
[Display(Name = "Phone Number")]
public int PhoneNumber { get; set; }
}
public class Commission
{
public int Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
}
public class Position
{
public int Id { get; set;}
public string Name { get; set; }
}
Note: I am using CodeFirst approach.
You can View thisexample to do that:
public class User
{
public int Id { get; set; }
public ICollection<UserAccount> UserAccounts { get; set; }
}
public class Account
{
public int Id { get; set; }
public ICollection<UserAccount> UserAccounts { get; set; }
}
public class UserAccount
{
public int UserId { get; set; }
public int AccountId { get; set; }
public int RoleId { get; set; }
public User User { get; set; }
public Account Account { get; set; }
public Role Role { get; set; }
}
public class Role
{
public int Id { get; set; }
public string RoleName { get; set; }
public ICollection<UserAccount> UserAccounts { get; set; }
}
Configuration:
modelBuilder.Entity<UserAccount>()
.HasKey(e => new { e.UserId, e.AccountId });
modelBuilder.Entity<UserAccount>()
.HasRequired(e => e.User)
.WithMany(e => e.UserAccounts)
.HasForeignKey(e => e.UserId);
modelBuilder.Entity<UserAccount>()
.HasRequired(e => e.Account)
.WithMany(e => e.UserAccounts)
.HasForeignKey(e => e.AccountId);
modelBuilder.Entity<UserAccount>()
.HasRequired(e => e.Role)
.WithMany(e => e.UserAccounts)
.HasForeignKey(e => e.RoleId);
You can create a new UserAccount in a several ways.
I've tried numerous examples on here and from the automapper wiki and I am still unable to get this issue resolved. I am trying to map a nested object and a nested collection and no matter what I do it always throws an error. The only way I can get the controller to return data is by turning on option.ignore for the two properties.
These are the business layer objects I am trying to map
public class LocationBL
{
public int Id { get; set; }
public string Name { get; set; }
public string Address { get; set; }
public string Address2 { get; set; }
public string City { get; set; }
public string State { get; set; }
public string Zipcode { get; set; }
public string Country { get; set; }
public DbGeography Coordinates { get; set; }
public int LocationType_Id { get; set; }
public virtual LocationTypeBL LocationType { get; set; }
public virtual ICollection<SportBL> Sports { get; set; }
}
public class LocationTypeBL
{
public int Id { get; set; }
public string Name { get; set; }
public virtual ICollection<LocationBL> Locations { get; set; }
}
public class SportBL
{
public int Id { get; set; }
public string Name { get; set; }
public virtual ICollection<LocationBL> Locations { get; set; }
public virtual ICollection<UserBL> Users { get; set; }
}
These are the data layer objects
public class Location : EntityData
{
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
[ForeignKey("Company")]
public int? CompanyId { get; set; }
[Required]
public string Name { get; set; }
public string Address { get; set; }
public string Address2 { get; set; }
public string City { get; set; }
public string State { get; set; }
public string Zipcode { get; set; }
public string Country { get; set; }
[Required]
public DbGeography Coordinates { get; set; }
[ForeignKey("LocationType")]
public int LocationType_Id { get; set; }
public virtual LocationType LocationType { get; set; }
public virtual ICollection<Sport> Sports { get; set; }
public virtual Company Company { get; set; }
}
public class LocationType : EntityData
{
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
public string Name { get; set; }
public virtual ICollection<Location> Locations { get; set; }
}
public class Sport : EntityData
{
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
[Required]
public string Name { get; set; }
public virtual ICollection<Location> Locations { get; set; }
public virtual ICollection<User> Users { get; set; }
}
This is my mapping profile
public class LocationProfile : Profile
{
public LocationProfile()
{
CreateMap<LocationType, LocationTypeBL>();
CreateMap<LocationTypeBL, LocationType>();
CreateMap<Location, LocationBL>()
.ForMember(Dest => Dest.Sports,
opt => opt.MapFrom(src => src.Sports))
.ForMember(Dest => Dest.LocationType,
opt => opt.MapFrom(src => src.LocationType));
CreateMap<LocationBL, Location>()
.ForMember(Dest => Dest.Sports,
opt => opt.MapFrom(src => src.Sports))
.ForMember(Dest => Dest.LocationType,
opt => opt.MapFrom(src => src.LocationType));
}
}
UPDATE *******
This is my LocationType profile
public class LocationTypeProfile : Profile
{
public LocationTypeProfile()
{
CreateMap<LocationType, LocationTypeBL>();
CreateMap<LocationTypeBL, LocationType>();
}
}
This is my Sport profile
public class SportProfile : Profile
{
public SportProfile()
{
CreateMap<Sport, SportBL>();
CreateMap<SportBL, Sport>();
}
}
Not sure if it matters but this is an Azure Mobile App backend using Autofac, WebAPI, and OWIN. This is my first time using AutoMapper and Autofac so please forgive me as I am still learning. The profiles are all registered and if I set the nested objects to ignore, the controller returns the proper data.
Thank you in advance!!!
You are almost there. You need to instruct AutoMapper on how to map the nested objects as well. So you need to create a map for the Sport to SportBL, and vice-versa, also.
// use ForMember if needed, but you know how to do that so I won't
// show it.
CreateMap<Sport, SportBL>();
Then AutoMapper will use that mapping when it mapping nested complex types.
Another note, if your classes have the same properties, you can just call the ReverseMap() method and it will do bidirectional mapping for you.
So instead of this:
CreateMap<LocationType, LocationTypeBL>();
CreateMap<LocationTypeBL, LocationType>();
You can just do this to accomplish the same thing:
Mapper.CreateMap<LocationType, LocationTypeBL>().ReverseMap();