I am using EF code first approach with fluent api. I am having one registration form in my application where in registering candidate can select multiple options from dropdown(Interested In Dropdown on Sign-Up form) that has a predefined set of options (which may increase in future but the chances are very rare). When the user submits the form I want to save this records to database. So I created following entities.
Participant Class where the registering candidates information will be saved
public class Participant
{
public Participant()
{
Interests = new Collection<Interest>();
}
[Key, ForeignKey("User")]
public int Id { get; set; }
[DisplayName("First Name")]
[StringLength(50, ErrorMessage = "First name cannot be more than 50 characters")]
[Required(ErrorMessage = "You must fill in first name")]
public string FirstName { get; set; }
[DisplayName("Last Name")]
[StringLength(50, ErrorMessage = "Last name cannot be more than 50 characters")]
[Required(ErrorMessage = "You must fill in last name")]
public string LastName { get; set; }
[Required(ErrorMessage = "You must indicate your full birthday")]
[DisplayName("Birthday")]
[DataType(DataType.DateTime)]
public DateTime BirthDate { get; set; }
[DisplayName("Gender")]
[Required(ErrorMessage = "You must select gender")]
public int Gender { get; set; }
public string Address { get; set; }
public int CountryId { get; set; }
public Country Country { get; set; }
[DisplayName("Zip code")]
[StringLength(10, ErrorMessage = "Zip code cannot be more than 10 characters")]
public string ZipCode { get; set; }
public string Mobile { get; set; }
public string PhotoUrl { get; set; }
public virtual User User { get; set; }
public virtual ICollection<Interest> Interests { get; set; }
public string MedicalConditions { get; set; }
}
Interest Class from where the Interested In dropdown on Sign-up form will get populate The user can select multiple options from the Interested In dropdown
Interest Class
public class Interest
{
public Interest()
{
Participants = new Collection<Participant>();
}
public int Id { get; set; }
public string InterestName { get; set; }
public virtual ICollection<Participant> Participants { get; private set; }
}
To hold each participants interest I created a ParticipantInterests table in DB with following schema. ParticipantInterests Id (PK) ParticipantId (FK from Participants table) InterestId (FK Interests table)
I added public virtual ICollection Participants { get; set; } in Interest model and
public virtual ICollection Interests { get; set; } in Participant model to form Many-To-Many association.
My Data Context class is as follows
public class STNDataContext : DbContext
{
public DbSet<Participant> Participants { get; set; }
public DbSet<User> Users { get; set; }
public DbSet<Country> Countries { get; set; }
public DbSet<Interest> Interests { get; set; }
public DbSet<Role> Roles { get; set; }
public DbSet<SecurityQuestion> SecurityQuestions { get; set; }
public DbSet<Tour> Tours { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Participant>()
.HasKey(p => p.Id);
modelBuilder.Entity<User>()
.HasOptional(u => u.Participant)
.WithRequired();
modelBuilder.Entity<Participant>()
.HasMany(p => p.Interests)
.WithMany(i => i.Participants)
.Map(m =>
{
m.ToTable("ParticipantInterests");
m.MapLeftKey("ParticipantId");
m.MapRightKey("InterestId");
});
modelBuilder.Entity<User>().HasRequired(u => u.Role);
modelBuilder.Entity<Participant>().HasRequired(p => p.Country);
modelBuilder.Entity<User>().HasOptional(u => u.SecurityQuestion);
}
public virtual void Commit()
{
base.SaveChanges();
}
Controller Action Code
public virtual ActionResult Register(StudentRegisterViewModel studentRegisterViewModel)
{
if (ModelState.IsValid)
{
if (_userService.IsUserExists(studentRegisterViewModel.Participant.User) == false)
{
studentRegisterViewModel.Participant.User.Username = studentRegisterViewModel.Username;
studentRegisterViewModel.Participant.User.Email = studentRegisterViewModel.Email;
studentRegisterViewModel.Participant.User.DateCreated = DateTime.Now;
studentRegisterViewModel.Participant.User.Id = 3;
studentRegisterViewModel.Participant.User.IsApproved = false;
studentRegisterViewModel.Participant.User.RoleId = 2;
studentRegisterViewModel.Participant.CountryId = 1;
var interests = new List<Interest>();
foreach (var interestItem in studentRegisterViewModel.SelectedInterests)
{
var interest = new Interest { Id = interestItem };
interest.Participants.Add(studentRegisterViewModel.Participant);
interests.Add(interest);
studentRegisterViewModel.Participant.Interests.Add(interest);
}
studentRegisterViewModel.Participant.Interests = interests;
_participantService.CreatParticipant(studentRegisterViewModel.Participant);
var user = _userService.GetUser(studentRegisterViewModel.Participant.User.Username);
}
}
studentRegisterViewModel.Gender =
Enum.GetNames(typeof(Gender)).Select(
x => new KeyValuePair<string, string>(x, x.ToString(CultureInfo.InvariantCulture)));
studentRegisterViewModel.Interests = _interestService.GetAllInterests();
return View(studentRegisterViewModel);
}
Participant Repository (DAL)
public class ParticipantRepository : Repository<Participant>, IParticipantRepository
{
public ParticipantRepository(IDatabaseFactory databaseFactory)
: base(databaseFactory)
{
}
}
Participant Service (BLL)
public class ParticipantService : IParticipantService
{
private readonly IParticipantRepository _participantRepository;
private readonly IUnitOfWork _unitOfWork;
public ParticipantService(IParticipantRepository participantRepository, IUnitOfWork unitOfWork)
{
this._participantRepository = participantRepository;
this._unitOfWork = unitOfWork;
}
public void CreatParticipant(Participant participant)
{
_participantRepository.Add(participant);
_unitOfWork.Commit();
}
}
Database Factory
public class DatabaseFactory : Disposable, IDatabaseFactory
{
private STNDataContext _stnDataContext;
public DatabaseFactory()
{
Database.SetInitializer<STNDataContext>(null);
}
public STNDataContext Get()
{
return _stnDataContext ?? (_stnDataContext = new STNDataContext());
}
protected override void DisposeCore()
{
if (_stnDataContext != null)
_stnDataContext.Dispose();
}
}
Unit of Work Class
public class UniOfWork : IUnitOfWork
{
private readonly IDatabaseFactory _databaseFactory;
private STNDataContext _stnDataContext;
public UniOfWork(IDatabaseFactory databaseFactory)
{
this._databaseFactory = databaseFactory;
}
public STNDataContext StnDataContext
{
get { return _stnDataContext ?? (_stnDataContext = _databaseFactory.Get()); }
}
public void Commit()
{
StnDataContext.Commit();
}
}
When I try to Create Participant I get following error.
Cannot insert the value NULL into column 'InterestName', table 'StudyTourNetworkDB.dbo.Interests'; column does not allow nulls. INSERT fails.\r\nThe statement has been terminated.
Ideally as per my thinking it should insert Participant Information in Participants table and Participants Interests in ParticipantsInterests table. But it is trying to insert record in Interests table also which should not happen. Please help me resolve this problem. I may be doing wrong by creating many-to-many association.
Thanks
Note : I could understand the problem as Interests collection does not get added / attach to context but I could not find out how to add Interest collection to the same context with repository pattern and unit of work.
Please provide me the solutions. Thanks in advance
You are correct in that your Interest objects are being re-added, because the copies held in your model are not being tracked by EF and therefore it thinks they are new. Instead, you will need to look up the versions from your repository, and add those instead.
Instead of:
var interests = new List<Interest>();
foreach (var interestItem in studentRegisterViewModel.SelectedInterests)
{
var interest = new Interest { Id = interestItem };
interest.Participants.Add(studentRegisterViewModel.Participant);
interests.Add(interest);
studentRegisterViewModel.Participant.Interests.Add(interest);
}
studentRegisterViewModel.Participant.Interests = interests;
Try something like:
// Look up the actual EF entities which match your selected items. You'll
// probably need to adapt this to make it work
var selectedInterestIds = studentRegisterViewModel.SelectedInterests.Select(i => i.Id);
var interests = _interestService.GetAllInterests().Where(i => selectedInterestIds.Contains(i.Id));
studentRegisterViewModel.Participant.Interests = interests;
Note that with a many-to-many relationship, you don't need to set both sides - in your example you were filling in the Participant field of the Interest entity - this will be set automatically by EF since you're adding it to the Interests property of the Participant.
Related
I'm using asp.net core Identity. The user ID will be as FK in the Invite model and I'm trying to display all the users that are in the invite
Models
public class Invite
{
public int ID { get; set; }
[ForeignKey("UserId")] //ICollection<Invite> in User
[Display(Name = "Users")]
public virtual ApplicationUser User { get; set; }
}
=================
public class ApplicationUser : IdentityUser
{
public string Description { get; set; }
[ForeignKey("GameID")]
public int? GameID { get; set; }
public string GameTag { get; set; }
public virtual ICollection<Invite> Invite { get; set; }
================
public class Game
{
public int ID { get; set; }
[Display(Name = "Game")]
public string GameName { get; set; }
public virtual ICollection<ApplicationUser> ApplicationUser { get; set; }//Allow Users to get Games FKID (Foreign key ID)
}
The getting the list of invites in the invite controller index and putting them inside viewbag for invite razor index page
this is where the error is coming from
if (i.User == tu.Id)
// GET: Invites
public async Task<IActionResult> Index()
{
ViewBag.InviteList = new List<String>();
var invite = _context.Invites;
var theuser = _context.ApplicationUser;
foreach (Invite i in invite)
{
foreach (ApplicationUser tu in theuser)
{
if (i.User == tu.Id)
{
ViewBag.InviteList.Add(tu.GameID + " " +tu.GameTag);
}
}
}
return View(await _context.Invites.ToListAsync());
}
Because i.User is an object of type ApplicationUser, it can't be compared to tu.Id which is (most likely) of type int.
You probably want to compare the IDs of the two ApplicationUser-Objects.
To do this, you need to use i.User.Id == tu.Id as the other comments have stated.
Maybe you meant to compare this
if (i.User == tu)
{
}
I am new to Entity Framework and Asp.NET, and therefore, struggling with creating database relationships within the Entity Framework.
I have two SQLite tables (Ticket and User) and have setup my entity models as follows:
public class Users
{
[ForeignKey("id")]
public int id { get; set; }
public string first_name { get; set; }
public string last_name { get; set; }
public string email { get; set; }
public virtual ICollection<Tickets> Tickets { get; set; }
}
public class Tickets
{
public int id { get; set; }
public string summary { get; set; }
public string description { get; set; }
public string c_location { get; set; }
public string c_store_device { get; set; }
public string category { get; set; }
public DateTime? created_at { get; set; }
public DateTime? closed_at { get; set; }
public int priority { get; set; }
public int? assigned_to { get; set; }
public DateTime? due_at { get; set; }
public DateTime? updated_at { get; set; }
public string status { get; set; }
public virtual Users Users { get; set; }
}
I am trying to use Entity Framework 7 to export an IEnumerable<Tickets> that includes the User assigned to each Ticket.
I have tried to create my model relationship in MyDBContext as a single User can have multiple Tickets, and also has a foreign key associated in my Sqlite database (Tickets.assigned_to = User.id):
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
// Users - > many Tickets
modelBuilder.Entity<Users>()
.HasMany(p => p.Tickets)
.WithOne(e => e.Users)
.HasForeignKey(p => p.assigned_to);
}
My result ends up with Ticket data being exported, but against every ticket I see a null value for User:
[{"id":10002,...,"Users":null}]
When I use .Include() within my Repository to include each User like this:
public IEnumerable<Tickets> GetAll()
{
return _db.Tickets.Include(t => t.Users).ToList();
}
It results in the error
HTTP Error 502.3 - Bad Gateway
The specified CGI application encountered an error and the server terminated the process.
What I'm trying to retrieve is data that looks like:
{"Ticket";[{"id":10002,..."status":"closed"}],"Users":[{"id":"1"..."email":"johndoe#someplace.com"}]}
I know it probably has something to do with my relationship model, but I cannot work out what I am doing wrong.
First you should really derive your Users from IdentityUser. It helps when trying to wire up the relationship, but I will give you the answer based on your current models. Your ForeignKey property should be on the child entity. By naming conventions, which is what EF uses by default, your public Users Users works better if you put a public int UsersId. Then essentially what EF will do is from your public Users Users it will go to the Users table. Then it looks for the ForeignKey which is set to Id, so now we are in the Users Table looking at the id property. Then it looks for the naming convention UsersId and if it sees it, it will set that property to the value that it saw from the Users Table Id column.
Try using this
public class Users
{
public int id { get; set; }
public string first_name { get; set; }
public string last_name { get; set; }
public string email { get; set; }
public virtual ICollection<Tickets> Tickets { get; set; }
}
public class Tickets
{
public int id { get; set; }
public string summary { get; set; }
public string description { get; set; }
public string c_location { get; set; }
public string c_store_device { get; set; }
public string category { get; set; }
public DateTime? created_at { get; set; }
public DateTime? closed_at { get; set; }
public int priority { get; set; }
public DateTime? due_at { get; set; }
public DateTime? updated_at { get; set; }
public string status { get; set; }
[ForeignKey("Id")]
public int UsersId { get; set; }
public virtual Users Users { get; set; }
}
and for your Fluent API configuring
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
// Users - > many Tickets
modelBuilder.Entity<Users>()
.HasMany(p => p.Tickets)
.WithOne();
}
Now all that does is create the relationship. In order to view the specific items you want to view, use a ViewModel. So, pull the two lists you want from where you want. Then use logic to separate the list how you want them to display.
public class UsersViewModel()
{
public UsersViewModel(Users user, List<Tickets> tickets)
{
this.first_name = user.first_name;
this.last_name = user.last_name;
this.email = user.email;
this.Tickets = new List<Tickets>();
foreach(var ticket in tickets)
{
if(ticket.UserId == user.Id)
{
this.Tickets.Add(ticket)
}
}
}
public string first_name { get; set; }
public string last_name { get; set; }
public string email { get; set; }
public List<Tickets> Tickets { get; set;}
}
then in your controller make your list
public IActionResult Index()
{
var usersList = _repository.Users.ToList();
var ticketsList = _repository.Tickets.ToList();
var model = new List<UsersViewModel>();
foreach(var user in usersList)
{
var listItem = new UsersViewModel(user, ticketsList);
model.Add(listItem);
}
return View(model);
}
or use a Linq query
public IActionResult Index()
{
var usersList = _repository.Users.ToList();
var model = new List<UsersViewModel>();
foreach(var user in usersList)
{
var ticketsList = from x in _repository.Tickets where x.UserId.Equals(user.Id) select x;
var listItem = new UsersViewModel(user, ticketsList);
model.Add(listItem);
}
return View(model);
}
then at the top of your view you should have
#model IEnumerable<UsersViewModel>
I have two tables. There is one-to-many relationship between these tables.I want to select Company table and BankAccount List table (for appropriate CompanyID).
How can I do it with Linq-to-Sql?
public class Company
{
// My Fields
[Key]
public Guid ID { get; set; }
public string FullName { get; set; }
// My virtual properties FOR relationships(one-to-one,one-to-many etc.).
public virtual List<BankAccount> BankAccounts { get; set; }
}
and
public class BankAccount
{
// My Fields
//[ScaffoldColumn(false)]
[Key]
public Guid ID { get; set; }
[ForeignKey("Companies")]
public Nullable<Guid> CompanyID { get; set; }
public string BankName { get; set; }
// My virtual properties FOR relationships(one-to-one,one-to-many etc.).
public virtual Company Company { get; set; }
}
I write this as follow, but I didn't like it
List<List<BankAccount>> bankaccounts = new List<List<BankAccount>>();
foreach (var comp in companyRepository.Companies)
{
List<BankAccount> banks = new List<BankAccount>();
foreach (var bank in bankRepository.BankAccounts)
{
if (comp.ID == bank.CompanyID)
{
banks.Add(bank);
}
}
bankaccounts.Add(banks);
banks = new List<BankAccount>();
}
I think the following will yield the same result.
var bankaccounts = companyRepository.Companies.Select(c => c.BankAccounts)
.ToList();
If you are using entity framework, you can eagerload the 'BankAccounts' property to minimize DB calls.
Hope this helps.
I am developing an ASP.NET MVC4 application with EF Code First. I am having a many-to-many relationship among following classes. I have defined relationship using EF fluent api in my context class. But I am getting an error as it is trying to insert values into one of my master table involved in many-to-many relation. Can anyone help me correct my problem. Thanks in advance and for valuable time.I am using repository pattern and unit of work with Ninject as dependency injection.
Participant Class
public class Participant
{
[Key]
public int Id { get; set; }
[DisplayName("First Name")]
[StringLength(50, ErrorMessage = "First name cannot be more than 50 characters")]
[Required(ErrorMessage = "You must fill in first name")]
public string FirstName { get; set; }
[DisplayName("Last Name")]
[StringLength(50, ErrorMessage = "Last name cannot be more than 50 characters")]
[Required(ErrorMessage = "You must fill in last name")]
public string LastName { get; set; }
[Required(ErrorMessage = "You must indicate your full birthday")]
[DisplayName("Birthday")]
[DataType(DataType.DateTime)]
public DateTime BirthDate { get; set; }
[DisplayName("Gender")]
[Required(ErrorMessage = "You must select gender")]
public int Gender { get; set; }
public string Address { get; set; }
public int CountryId { get; set; }
public Country Country { get; set; }
[DisplayName("Zip code")]
[StringLength(10, ErrorMessage = "Zip code cannot be more than 10 characters")]
public string ZipCode { get; set; }
public string Mobile { get; set; }
public string PhotoUrl { get; set; }
public int UserId { get; set; }
public User User { get; set; }
public virtual ICollection<Interest> Interests { get; set; }
}
Interest Class
public class Interest
{
public int Id { get; set; }
public string InterestName { get; set; }
public virtual ICollection<Participant> Participants { get; set; }
}
DataContext
public class STNDataContext : DbContext
{
public DbSet<User> Users { get; set; }
public DbSet<Participant> Participants { get; set; }
public DbSet<Country> Countries { get; set; }
public DbSet<Interest> Interests { get; set; }
public DbSet<Role> Roles { get; set; }
public DbSet<SecurityQuestion> SecurityQuestions { get; set; }
public DbSet<Tour> Tours { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Participant>().
HasMany(p => p.Interests).
WithMany(i => i.Participants).
Map(
m =>
{
m.ToTable("ParticipantInterests");
m.MapLeftKey("ParticipantId");
m.MapRightKey("InterestId");
});
modelBuilder.Entity<User>().HasRequired(u => u.Role);
modelBuilder.Entity<Participant>().HasRequired(p => p.Country);
}
public virtual void Commit()
{
base.SaveChanges();
}
}
Controller Code
public virtual ActionResult Register(StudentRegisterViewModel studentRegisterViewModel)
{
if (ModelState.IsValid)
{
if (_userService.IsUserExists(studentRegisterViewModel.Participant.User) == false)
{
// Attempt to register the user
//WebSecurity.CreateUserAndAccount(model.UserName, model.Password);
//WebSecurity.Login(model.UserName, model.Password);
studentRegisterViewModel.Participant.User.Username = studentRegisterViewModel.Username;
studentRegisterViewModel.Participant.User.Email = studentRegisterViewModel.Email;
studentRegisterViewModel.Participant.User.DateCreated = DateTime.Now;
studentRegisterViewModel.Participant.User.Id = 3;
studentRegisterViewModel.Participant.User.IsApproved = false;
studentRegisterViewModel.Participant.User.RoleId = 2;
studentRegisterViewModel.Participant.CountryId = 1;
var participant = new Participant
{
Id = studentRegisterViewModel.Participant.Id,
FirstName = studentRegisterViewModel.Participant.FirstName,
LastName = studentRegisterViewModel.Participant.LastName,
Interests = new Collection<Interest>()
};
var interests = new List<Interest>();
foreach (var interestItem in studentRegisterViewModel.SelectedInterests)
{
var interest = new Interest { Id = interestItem, Participants = new Collection<Participant>() };
interest.Participants.Add(participant);
interests.Add(interest);
}
studentRegisterViewModel.Participant.Interests = interests;
_participantService.CreatParticipant(studentRegisterViewModel.Participant);
//_userService.CreatUser(studentRegisterViewModel.Participant.User);
//TODO: Need to check if do we need to register the user and get him signed-in. If yes signing in implementation goes here.
var user = _userService.GetUser(studentRegisterViewModel.Participant.User.Username);
//Session["User"] = user;
//FormsAuthentication.SetAuthCookie(user.Username, false);
//Growl("Welcome", "Thanks for registering and welcome to Truck Tracker.");
//return RedirectToAction("Index", "Home");
}
}
//return RedirectToAction("Index", "Home");
// If we got this far, something failed, redisplay form
studentRegisterViewModel.Gender =
Enum.GetNames(typeof(Gender)).Select(
x => new KeyValuePair<string, string>(x, x.ToString(CultureInfo.InvariantCulture)));
studentRegisterViewModel.Interests = _interestService.GetAllInterests();
return View(studentRegisterViewModel);
}
Ideally it should insert Participant into Participants Table and Participant Interests in ParticipantInterests many-to-many table. But it is giving following error
{"Cannot insert the value NULL into column 'InterestName', table 'StudyTourNetworkDB.dbo.Interests'; column does not allow nulls. INSERT fails.\r\nThe statement has been terminated."}
It is trying to insert into Interests table which should not happen.
Participant ParticipantInterests Interests
Id Id Id
FirstName ParticipantId InterestName
LastName InterestId
This is how the tables in the database. The Interest table has a fixed set of records(Study, Job, Other,etc) which get displayed in Interested In dropdown. The registering participant can select multiple interested in options and when he clicks Sign Up button the Participant record will get saved in Participant Table and selected Interests in ParticipantInterests table.
Thanks
I was messing around with the same things the other day. Pain to get it figured out but here is a very basic example of a many to many I got working:
namespace Project.Models
{
public class Affiliate
{
public Affiliate()
{
Merchants = new HashSet<Merchant>();
}
public int Id { get; set; }
public ICollection<Merchant> Merchants { get; set; }
}
}
namespace Project.Models
{
public class Merchant
{
public Merchant()
{
Affiliates = new HashSet<Affiliate>();
}
public int Id { get; set; }
public ICollection<Affiliate> Affiliates{ get; set; }
}
}
and in the DbContext I did this:
modelBuilder.Entity<Merchant>().
HasMany(c => c.Affiliates).
WithMany(p => p.Merchants).
Map(
m =>
{
m.MapLeftKey("MerchantId");
m.MapRightKey("AffiliateId");
m.ToTable("MerchantAffiliates");
});
Update
I am trying to understand what you are looking to accomplish. It seems like this:
A participant can be interested in many things. Multiple participants can be interested in the same thing. If that is the fact I would consider changing the model so a participant has a list of interests, but the interests table, in my opinion, does not need a list of participants. If you wanted to retrieve say all participants with an interest in hiking you could just do something like this:
Context.Participants.ToList().Where(x => x.Interest.Name == "hiking");
Make sense?
I have two Entities in an MVC app:
public class User
{
public int ID {get; set;}
public string Forename {get; set;}
public string Surname {get;set;}
}
public class SubGroup
{
public int ID {get;set;}
public string Name {get;set;}
}
and I want to use Code First to create a relationship between them. The relationship is that each user can be a member of 0 or more subgroups.
Please can someone suggest the best way to do this because I have seen a few examples on SO and I'm confused. I've seen stuff about implementing ICollections in a class, other stuff about using the fluent API.
ICollections approach:
UPDATE:
If I understand correctly you have many-to-many relationship (group have many users, user have can be in many groups), in that case code should be like this:
public class RelationExampleContext : DbContext
{
public DbSet<User> Users { get; set; }
public DbSet<SubGroup> SubGroups { get; set; }
}
public class User
{
[Key]
public int ID { get; set; }
public string Forename { get; set; }
public string Surname { get; set; }
public ICollection<SubGroup> SubGroups { get; set; }
}
public class SubGroup
{
[Key]
public int ID { get; set; }
public string Name { get; set; }
public ICollection<User> Users { get; set; }
}
Adding Users to groups example:
var db = new RelationExampleContext();
var subGroups = new List<SubGroup>
{
new SubGroup() {Name = "Subgroup1"},
new SubGroup() {Name = "Subgroup2"}
};
var users = new List<User>
{
new User()
{
Forename = "Forename1",
Surname = "Surname1",
SubGroups = new List<SubGroup>
{
subGroups.First(),
subGroups.Last()
}
},
new User()
{
Forename = "Forename2",
Surname = "Surname2",
SubGroups = new List<SubGroup>
{
subGroups.First()
}
}
};
foreach (var subGroup in subGroups)
{
db.SubGroups.Add(subGroup);
}
foreach (var user in users)
{
db.Users.Add(user);
}
db.SaveChanges();
I guess User and SubGroup has the same Tables in database
you need create relation table between this tables (fields User_id, Group_id)
model for new entity like UserGroups
and then you can create composition in User class