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?
Related
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 3 tables that are connected together as follows:
Survey
public enum Language
{
Danish,
English
}
public class Survey
{
public Survey()
{
Id = Guid.NewGuid();
DateCreated = DateTime.Now;
Sort = 0;
}
[Key]
public Guid Id { get; set; }
public bool Active { get; set; }
public string Title { get; set; }
public bool Status { get; set; }
[Display(Name = "Kommentar")]
public string Comment { get; set; }
public string MAilReciever { get; set; }
public string CCMailReciever { get; set; }
public string BBCMailReciever { get; set; }
public int Sort { get; set; }
public DateTime DateCreated { get; set; }
public string StartText { get; set; }
public string EndText { get; set; }
public string RegardText { get; set; }
public Language Language { get; set; }
public virtual ICollection<UserSurvey> UserSurveys { get; set; }
public virtual ICollection<Chapters> Chapters { get; set; }
public virtual ICollection<Questions> Questions { get; set; }
}
ApplicationUser
The default ApplicationUser table from Mvc with identity.
UserSurvey (My relationShipTable between Survey and ApplicationUser)
public class UserSurvey
{
[Key, Column(Order = 0)]
public Guid SurveyId { get; set; }
[Key, Column(Order = 1)]
public string ApplicationUserId { get; set; }
public virtual Survey Survey { get; set; }
public virtual ApplicationUser ApplicationUser { get; set; }
public bool Active { get; set; }
public DateTime StartDate { get; set; }
public DateTime EndDate { get; set; }
public string RegardText { get; set; }
}
I'm trying to add a new relation between a user and a servey by the following code:
UserSurvey Item = new UserSurvey();
Item.Survey = s;
Item.ApplicationUser = userinfo;
Item.Active = true;
Item.StartDate = Convert.ToDateTime(dateFrom);
Item.EndDate = Convert.ToDateTime(dateTo);
db.UserSurvey.Add(Item);
db.SaveChanges();
The error message I get says that I cant "Duplicate the SurveyId primary key because it already exist in the database (table survey).
I know it exist but I just want to make a relation between users and surveys, not create a new survey or user.
Thanks for your help
Your problem is that you are providing a completed UserSurvey object with nested objects (Survey/ApplicationUser) populated. When you do that and set the changeset as "Add" (caused by db.UserSurvey.Add(Item);). EF will attempt to issue INSERT INTO for the parent (UserSurvey) and all child/related(Survey/ApplicationUser) tables since it thinks that the "Add" changeset applies to all of these tables. To resolve your issue, you need to just provide the Ids. That will just insert a new relationship:
UserSurvey Item = new UserSurvey();
//Item.Survey = s; //This object filling is making EF believe that you are attempting to add a new record in Survey. Comment it out
//Item.ApplicationUser = userinfo; //This object filling is making EF believe that you are attempting to add a new record in ApplicationUser. Comment it out
Item.ApplicationUserId = userinfo.ApplicationUserId;//or whatever is the id column name in ApplicationUser table/class
Item.SurveyId = s.SurveyId;//I see that you are missing SurveyId property in UserSurvey. You will need to add this. This will be the Foreign Key to Survey table just like you have ApplicationUserId FK to ApplicationUser table.
Item.Active = true;
Item.StartDate = Convert.ToDateTime(dateFrom);
Item.EndDate = Convert.ToDateTime(dateTo);
db.UserSurvey.Add(Item);
db.SaveChanges();
So, the underlying idea is to fill the Ids if the nested records (Survey/Application in this case) already exist. You only populated nested object when you want EF to attempt to INSERT them too for you. Dont populate them if you dont want this. Just the Ids help EF to create just the relationship and not go after creating these related records again for you.
Hope this helps.
Imagine the person Ted. Ted use bulletin board. He can post ads and subscribe to ads (imagine ad is some event.. teaching lessons for example). So as you guessed we have two objects: Advert and User (Ted). One user posts different adverts and in the other hand one user subscribes for different adverts. So we have two types of relationships: One-to-Many (Ted to his adverts) and Many-to-Many (Advert to subscribers - subscriber to adverts).
So the Models looks like:
[Table("Users")]
public class User
{
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
[Display(Name="Login")]
[Required(ErrorMessage = "Enter the login.")]
public string Name { get; set; }
[Required(ErrorMessage = "Select the city.")]
public int CityId { get; set; }
public City City { get; set; }
public int? SpecialityId { get; set; }
public Speciality Speciality { get; set; }
public virtual ICollection<Advert> Adverts { get; set; }
public virtual ICollection<Advert> SubscribedOnAdverts { get; set; }
public User()
{
Adverts = new List<Advert>();
SubscribedOnAdverts = new List<Advert>();
}
}
And Advert:
public class Advert
{
public int Id { get; set; }
[Required(ErrorMessage = "Enter your ad title")]
public string Title { get; set; }
[Required(ErrorMessage = "Enter your ad text")]
[Display(Name="Advert text")]
public string Description { get; set; }
public int? Price { get; set; }
[DisplayName("Owner")]
[Required(ErrorMessage = "Select ad owner")]
public int UserId { get; set; }
public User User { get; set; }
[DisplayName("Speciality")]
[Required(ErrorMessage = "Enter the speciality")]
public int SpecialityId { get; set; }
public Speciality Speciality { get; set; }
[Column(TypeName = "DateTime2")]
public DateTime publishTime { get; set; }
public virtual ICollection<User> SubscribedUsers { get; set; }
public Advert() {
publishTime = DateTime.Now;
SubscribedUsers = new List<User>();
}
}
Let's look at the User model: you can see the same type of props: Adverts, SubscripedOnAdverts. If we delete SubscribedOnAdverts property from the User model and SubscribedUsers from the Advert model, following code will perfom correct:
IEnumerable<Advert> userAdverts = db.Users.Where(usr => usr.Id == id).FirstOrDefault().Adverts;
It will return adverts this user posted.
But with the above properies (SubscribedOnAdverts in User model, SubscribedUsers in Advert model) it will return empty Collection.
Normal:
With problem:
I can guess why it happens. But i don't know how to fix this issue and save the relationships.
In my application, I am trying to write a ListStudents ActionResult that will only display a list of students whose ClassroomID is equal one of the ClassroomID's that the currently logged on teacher has created.
I believe that I need to use a few LINQ queries to get the desired result but I am stuck because I do not quite know how to handle it when the teacher entity has an ICollection of classrooms.
ListStudents & CreateClassroom in my TeacherController
public ActionResult ListStudents()
{
//This gets the current teachers UserProfile as only users with the teacher role have access to this controller
var teacherProfile = db.UserProfiles.Local.SingleOrDefault(u => u.UserName == User.Identity.Name)
?? db.UserProfiles.SingleOrDefault(u => u.UserName == User.Identity.Name);
var teacher = db.Teachers.Find(teacherProfile.UserId);
//Need query where students ClassroomID needs to be one of the current teachers ClassroomID's
return View(students);
}
public ActionResult CreateClassroom(Classroom model)
{
if (ModelState.IsValid)
{
try
{
var userProfile = db.UserProfiles.Local.SingleOrDefault(u => u.UserName == User.Identity.Name)
?? db.UserProfiles.SingleOrDefault(u => u.UserName == User.Identity.Name);
var classroom = new Classroom
{
ClassroomName = model.ClassroomName,
TeacherID = userProfile.UserId
};
db.Classrooms.Add(classroom);
db.SaveChanges();
}
catch (DataException)
{
ModelState.AddModelError("", "Something went wrong, try again.");
}
}
return RedirectToAction("ListClassrooms");
}
Models For User, Student, Teacher, and Classroom
public class User
{
[Key]
[Editable(false)]
[ForeignKey("UserProfile")]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.None)]
public int UserId { get; set; }
public virtual UserProfile UserProfile { get; set; }
[Display(Name = "First Name")]
[Required(ErrorMessage = "First name is required.")]
[MaxLength(50)]
public virtual string FirstName { get; set; }
[Display(Name = "Last Name")]
[Required(ErrorMessage = "Last name is required.")]
[MaxLength(50)]
public virtual string LastName { get; set; }
}
Student
public class Student : User
{
[ForeignKey("Account")]
[Editable(false)]
public virtual int AccountID { get; set; }
public virtual Account Account { get; set; }
[Column("ClassroomID")]
[ForeignKey("Classroom")]
public virtual int ClassroomID { get; set; }
public virtual Classroom Classroom { get; set; }
}
Teacher
public class Teacher : User
{
public virtual ICollection<Classroom> Classrooms { get; set; }
}
Classroom
public class Classroom
{
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public virtual int ClassroomID { get; set; }
[Display(Name = "Classroom Name")]
[MaxLength(50)]
public virtual string ClassroomName { get; set; }
public virtual ICollection<Student> Students { get; set; }
[Column("TeacherID")]
[ForeignKey("Teacher")]
public virtual int TeacherID { get; set; }
public virtual Teacher Teacher { get; set; }
}
Thank you for your time to help me solve this, I am very new to MVC and am trying to learn as much as I can.
Broken out into a couple lines which makes it easier to understand.
var classrooms = db.Classrooms.Where(x => x.TeacherID == teacher.Id).Select(x => x.ClassroomID);
var students = db.Students.Where(x => classrooms.Contains(x.ClassroomID);
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.