I have two model in my project, SupplierRow.cs
using System;
namespace Argussite.SupplierServices.ViewModels
{
public class SupplierRow
{
public Guid Id { get; set; }
public string FullName { get; set; }
public bool Subscribed { get; set; }
public bool Active { get; set; }
public int Visits { get; set; }
}
}
and UserRow.cs
using System;
namespace Argussite.SupplierServices.ViewModels
{
public class UserRow
{
public Guid Id { get; set; }
public string FullName { get; set; }
public string Name { get; set; }
public string Email { get; set; }
public int Status { get; set; }
public int Role { get; set; }
}
}
then I use the first model in one controller
public ActionResult Grid(bool? active)
{
var page = Context.Suppliers.AsNoTracking()
.WhereIf(active != null, e => e.Active == active)
.Select(e => new SupplierRow
{
Id = e.Id,
FullName = e.FullName,
Active = e.Active,
Visits = e.Visits
})
.ToList();
return PartialView("_Grid", page);
}
and use the second model in other controller
public class AdminSuppliersAccountsController : BaseController
{
public ActionResult Index(Guid id)
{
var supplierOfUser = Context.Suppliers.AsNoTracking()
//.Include(e => e.Supplier)
.FirstOrDefault(e => e.Id == id);
ViewData.Add("id", id);
ViewData.Add("SupplierFullName", supplierOfUser.FullName);
return View();
}
public ActionResult Grid(int? status, Pager pager, Guid? supplierId)
{
var page = Context.Users.AsNoTracking()
.Where(e => e.SupplierId == supplierId)
.WhereIf(status != null, e => (e.Status == status))
.Select(e => new UserRow
{
Id = e.Id,
FullName = e.FullName,
Email = e.Email,
Name = e.Name,
Status = e.Status,
Role = e.Role
})
.GetPage(pager, Sorter.Asc<UserRow, string>(e => e.FullName));
return PartialView("_Grid", page);
}
but I need to add in the first controller checking if all users from second model have status Inactive and then use that in the view.
How can I do that?
I guess, I need to add a new property in the first model public bool AllUnactive { get; set; } but what should I do then?
Related
As in question: is primary key in join table needed?
I have job table:
public partial class Job
{
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
public Job()
{
this.Room = new HashSet<Room>();
}
public int JobID { get; set; }
public string Title { get; set; }
public Nullable<int> DepartmentID { get; set; }
public virtual Department Department { get; set; }
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
public virtual ICollection<Room> Room { get; set; }
}
And user table:
public partial class AspNetUsers
{
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
public AspNetUsers()
{
this.Department = new HashSet<Department>();
}
public string Id { get; set; }
public string Email { get; set; }
public bool EmailConfirmed { get; set; }
public string PasswordHash { get; set; }
public string SecurityStamp { get; set; }
public string PhoneNumber { get; set; }
public bool PhoneNumberConfirmed { get; set; }
public bool TwoFactorEnabled { get; set; }
public Nullable<System.DateTime> LockoutEndDateUtc { get; set; }
public bool LockoutEnabled { get; set; }
public int AccessFailedCount { get; set; }
public string UserName { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public Nullable<int> PhoneNo { get; set; }
public Nullable<System.DateTime> HireDate { get; set; }
public Nullable<System.DateTime> BirthDate { get; set; }
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
public virtual ICollection<Department> Department { get; set; }
}
Every user can be in few departments, and every deparment can have many users.
In my controller:
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Linq;
using System.Net;
using System.Web;
using System.Web.Mvc;
using Praca.Models;
using Praca.ViewModels;
namespace Praca.Controllers
{
public class EmployeeController : Controller
{
private Entities1 db = new Entities1();
// GET: Employee
public ActionResult Index(string id)
{
var viewModel = new AspNetUserDepartmentVM();
viewModel.AspNetUsers = db.AspNetUsers
.Include(i => i.Department)
.OrderBy(i => i.LastName);
if (id != null)
{
ViewBag.EmployeeID = id;
viewModel.Departments = viewModel.AspNetUsers.Where(
i => i.Id == id).Single().Department;
}
return View(viewModel);
}
// GET: Employee/Details/5
public ActionResult Details(string id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
AspNetUsers aspNetUsers = db.AspNetUsers.Find(id);
if (aspNetUsers == null)
{
return HttpNotFound();
}
return View(aspNetUsers);
}
// GET: Employee/Create
public ActionResult Create()
{
return View();
}
// POST: Employee/Create
// To protect from overposting attacks, please enable the specific properties you want to bind to, for
// more details see https://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include = "Id,Email,EmailConfirmed,PasswordHash,SecurityStamp,PhoneNumber,PhoneNumberConfirmed,TwoFactorEnabled,LockoutEndDateUtc,LockoutEnabled,AccessFailedCount,UserName,FirstName,LastName,PhoneNo,HireDate,BirthDate")] AspNetUsers aspNetUsers)
{
if (ModelState.IsValid)
{
db.AspNetUsers.Add(aspNetUsers);
db.SaveChanges();
return RedirectToAction("Index");
}
return View(aspNetUsers);
}
// GET: Employee/Edit/5
public ActionResult Edit(string id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
AspNetUsers aspNetUsers = db.AspNetUsers
.Include(i => i.Department)
.Where(i => i.Id == id)
.Single();
PopulateAssignedCourseData(aspNetUsers);
if (aspNetUsers == null)
{
return HttpNotFound();
}
return View(aspNetUsers);
}
private void PopulateAssignedCourseData(AspNetUsers aspNetUsers)
{
var allCourses = db.Department;
var instructorCourses = new HashSet<int>(aspNetUsers.Department.Select(c => c.DepartmentID));
var viewModel = new List<AssignedDepartment>();
foreach (var course in allCourses)
{
viewModel.Add(new AssignedDepartment
{
DepartmentID = course.DepartmentID,
DepartmentName = course.DepartmentName,
Assigned = instructorCourses.Contains(course.DepartmentID)
});
}
ViewBag.Courses = viewModel;
}
// POST: Employee/Edit/5
// To protect from overposting attacks, please enable the specific properties you want to bind to, for
// more details see https://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Edit(string id, string[] selectedCourses)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
var instructorToUpdate = db.AspNetUsers
.Include(i => i.Department)
.Where(i => i.Id == id)
.Single();
if (TryUpdateModel(instructorToUpdate, "",
new string[] { "LastName"}))
{
try
{
UpdateInstructorCourses(selectedCourses, instructorToUpdate);
db.SaveChanges();
return RedirectToAction("Index");
}
catch (RetryLimitExceededException /* dex */)
{
//Log the error (uncomment dex variable name and add a line here to write a log.
ModelState.AddModelError("", "Unable to save changes. Try again, and if the problem persists, see your system administrator.");
}
}
PopulateAssignedCourseData(instructorToUpdate);
return View(instructorToUpdate);
}
private void UpdateInstructorCourses(string[] selectedCourses, AspNetUsers instructorToUpdate)
{
if (selectedCourses == null)
{
instructorToUpdate.Department = new List<Department>();
return;
}
var selectedCoursesHS = new HashSet<string>(selectedCourses);
var instructorCourses = new HashSet<int>
(instructorToUpdate.Department.Select(c => c.DepartmentID));
foreach (var course in db.Department)
{
if (selectedCoursesHS.Contains(course.DepartmentID.ToString()))
{
if (!instructorCourses.Contains(course.DepartmentID))
{
instructorToUpdate.Department.Add(course);
}
}
else
{
if (instructorCourses.Contains(course.DepartmentID))
{
instructorToUpdate.Department.Remove(course);
}
}
}
}
// GET: Employee/Delete/5
public ActionResult Delete(string id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
AspNetUsers aspNetUsers = db.AspNetUsers.Find(id);
if (aspNetUsers == null)
{
return HttpNotFound();
}
return View(aspNetUsers);
}
// POST: Employee/Delete/5
[HttpPost, ActionName("Delete")]
[ValidateAntiForgeryToken]
public ActionResult DeleteConfirmed(string id)
{
AspNetUsers aspNetUsers = db.AspNetUsers.Find(id);
db.AspNetUsers.Remove(aspNetUsers);
db.SaveChanges();
return RedirectToAction("Index");
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
db.Dispose();
}
base.Dispose(disposing);
}
}
}`
Unfortunately I have error: Unable to update the EntitySet 'AspNetUsersDepartment' because it has a DefiningQuery and no element exists in the element to support the current operation.
How can I solve this problem?
When i set primary key on that table, there is no many to many relationship but two one to many's relations.
OK. I have figuerd it out for myself..
If anyone also have this kind of problem:
You have to set primary keys, but not as separate value in your table.
In my case
CONSTRAINT [PK_dbo.AspNetUserDepartment] PRIMARY KEY CLUSTERED ([EmployeeId] ASC, [DepartmentId] ASC),
works perfectly.
I'm getting this error:
The INSERT statement conflicted with the FOREIGN KEY constraint "FK_dbo.ConsoleUserInfoes_dbo.ConsolesCheckBoxes_consoleId". The conflict occurred in database "aspnet-ForePlay-20180525122039", table "dbo.ConsolesCheckBoxes", column 'ConsoleId'.
I'm using Entity Framework and ASP.NET MVC 5 and IdentityUser and try to insert data form checkListBox to table into my database.
This is happening on the register view, when user need to register and fill the form.
public class ConsoleUserInfo
{
[Key]
public int identity { get; set; }
[Required]
[StringLength(255)]
[ForeignKey("User")]
public string userid { get; set; }
[Required]
[ForeignKey("consolesCheckBox")]
public int consoleId { get; set; }
public virtual ApplicationUser User { get; set; }
public virtual ConsolesCheckBox consolesCheckBox { get; set; }
}
This is the table that need to get a user id (form applictionUser) and consoleId
(form ConsolesCheckBox )
This is the ApplicationUserUser model class:
public class ApplicationUser : IdentityUser
{
[Required]
[StringLength(255)]
override
public string UserName { get; set; }
[Required]
[StringLength(50)]
public string Phone { get; set; }
public byte[] UserPhoto { get; set; }
public virtual UserAddress Address { get; set; }
public virtual ICollection<ConsolesCheckBox> consoleCheckBox { get; set; }
}
and this is the checkBoxList table:
public class ConsolesCheckBox
{
[Key]
public int ConsoleId { get; set; }
public string ConsoleName { get; set; }
public bool IsChecked { get; set; }
public virtual ICollection<ApplicationUser> ApplicationUser { get; set; }
}
This is my account controller, all in the register get and post
// GET: /Account/Register
[AllowAnonymous]
public ActionResult Register()
{
//using database
using (ApplicationDbContext dbo = new ApplicationDbContext())
{
//data will save list of the consoleCheckBoxItem
var data = dbo.consolesCheckBox.ToList();
// because the view is request a common model, we will create new one
CommenModel a = new CommenModel();
a.ConsolesCheckBoxList = data;
// we will need to return common model, that way we will return a
return View(a);
}
}
//
// POST: /Account/Register
[HttpPost]
[AllowAnonymous]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Register([Bind(Exclude = "UserPhoto")]CommenModel model)
{
if (ModelState.IsValid)
{
// To convert the user uploaded Photo as Byte Array before save to DB
byte[] imageData = null;
if (Request.Files.Count > 0)
{
HttpPostedFileBase poImgFile = Request.Files["UserPhoto"];
using (var binary = new BinaryReader(poImgFile.InputStream))
{
imageData = binary.ReadBytes(poImgFile.ContentLength);
}
}
var user = new ApplicationUser
{
UserName = model.registerViewModel.Email,
Email = model.registerViewModel.Email,
Phone = model.registerViewModel.Phone
};
user.UserPhoto = imageData;
var result = await UserManager.CreateAsync(user, model.registerViewModel.Password);
//after the user create, we will use the id and add the id to the userAddress table include
// Address, longitude and latitude.
using (ApplicationDbContext dbo = new ApplicationDbContext())
{
var currentUserId = user.Id;
var pasinfo = dbo.userAddress.FirstOrDefault(d => d.Userid == currentUserId);
if (pasinfo == null)
{
pasinfo = dbo.userAddress.Create();
pasinfo.Userid = currentUserId;
dbo.userAddress.Add(pasinfo);
}
pasinfo.Address = model.useraddress.Address;
pasinfo.latitude = model.useraddress.latitude;
pasinfo.longitude = model.useraddress.longitude;
dbo.SaveChanges();
foreach (var item in model.ConsolesCheckBoxList.Where(x => x.IsChecked).Select(x => x.ConsoleId))
{
var consoleUserInfo = new ConsoleUserInfo
{
userid = currentUserId,
consoleId = item
};
dbo.consoleUserInfo.Add(consoleUserInfo);
}
dbo.SaveChanges();
}
}
}
In the register GET I have a common model, because I used 3 models in the view
this is the common model:
public class CommonModel
{
public UserAddress useraddress { get; set; }
public RegisterViewModel registerViewModel { get; set; }
public List<ConsolesCheckBox> ConsolesCheckBoxList { get; set; }
}
I need your help here, I've been trying to fix this all day.
I have
class User {
...
...
ICollection<Transaction> transactionsUserMade;
}
and
class Transaction {
int ID;
int userThatSentMoneyID;
int userToWhomHeSentMoneyID;
}
I'm trying to make profile page where user can see all transactions he made and to whom. I managed to relate users and transaction but I'm getting integer values, as i should by using
await _context.Users
.Include(u => u.transactionsUserMade)
.AsNoTracking()
.FirstOrDefaultAsync(u => u.ID == userId);
How can i turn those ID's to actual objects of Users so i could get their usernames and display them on Razor Page.
Found one solution. I tweaked Transaction class by adding User userThatRecievedMoney property. And after getting transactions from specific user i manually set that property.
foreach(var transaction in _user.transactionsUserMade)
{
transaction.userThatRecievedMoney = _context.Users
.Where(u => u.ID == transaction.userToWhomHeSentMoneyID).FirstOrDefault();
}
You can use Navigation Property to help you with that as long as you can modify those entity models User and Transaction.
public class UserEntity
{
public int Id { get; set; }
public string Name { get; set; }
public string Email { get; set; }
public List<TransactionEntity> TransactionsAsSender { get; set; }
public List<TransactionEntity> TransactionsAsRecipient { get; set; }
}
public class TransactionEntity
{
public int Id { get; set; }
public double Amount { get; set; }
public string Note { get; set; }
// Foreign key to UserEntity
public int SenderId { get; set; }
public UserEntity Sender { get; set; }
// Foreign key to UserEntity
public int RecipientId { get; set; }
public UserEntity Recipient { get; set; }
}
Then you need to setup their relationships.
public class AppDbContext : DbContext
{
public AppDbContext(DbContextOptions<AppDbContext> options) : base(options) {}
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
builder.Entity<UserEntity>(b => {
b.HasKey(x => x.Id);
b.Property(x => x.Name).IsRequired();
b.Property(x => x.Email).IsRequired();
b.ToTable("User");
});
builder.Entity<TransactionEntity>(b => {
b.HasKey(x => x.Id);
b.Property(x => x.Amount).IsRequired();
// Configure relationships
b.HasOne(x => x.Sender)
.WithMany(u => u.TransactionsAsSender)
.HasForeignKey(x => x.SenderId);
b.HasOne(x => x.Recipient)
.WithMany(u => u.TransactionsAsRecipient)
.HasForeignKey(x => x.RecipientId);
b.ToTable("Transaction");
});
}
public DbSet<UserEntity> Users { get; set; }
public DbSet<TransactionEntity> Transactions { get; set; }
}
After their relationships are setup, you can easily query the related data via navigation properties.
For example, let's say you have view model called UserProfileViewModel and UserProfileTransactionViewModel to contain the information it needs for display purpose.
public class UserProfileViewModel
{
public int UserId { get; set; }
public string UserName { get; set; }
public string UserEmail { get; set; }
public IEnumerable<UserProfileTransactionViewModel> TransactionsAsSender { get; set; }
public IEnumerable<UserProfileTransactionViewModel> TransactionsAsRecipient { get; set }
}
public class UserProfileTransactionViewModel
{
public int TransactionId { get; set; }
public string Sender { get; set; }
public string Recipient { get; set; }
public string Amount { get; set; }
}
In the controller,
var user = _dbContext.Users
.AsNoTracking()
.Include(x => x.TransactionsAsSender)
.Include(x => x.TransactionsAsRecipient)
.SingleOrDefault(x => x.Id == userId);
if (user == null)
{
return NotFound();
}
var vm = new UserProfileViewModel
{
UserId = user.Id,
UserName = user.Name,
UserEmail = user.Email,
TransactionsAsSender = user.TransactionsAsSender
.Select(x => new UserProfileTransactionViewModel
{
TransactionId = x.Id,
Sender = x.Sender.Name,
Recipient = x.Recipient.Name,
Amount = x.Amount.ToString("c")
}),
TransactionsAsRecipient = user.TransactionsAsRecipient
.Select(x => new UserProfileTransactionViewModel
{
TransactionId = x.Id,
Sender = x.Sender.Name,
Recipient = x.Recipient.Name,
Amount = x.Amount.ToString("c")
})
};
return View(vm);
You could even have just a list of all transactions off UserProfileViewModel. You can combine TransactionsAsSender and TransactionsAsRecipient from UserEntity to fill the list.
Disclaim:
I wrote everything by hand and with my imagination :p
I'm using Entity Framework Core to build a simple web app. For this app, I've created a model called Company that includes basic business info + a list of contacts (sales reps).
Here's my model:
public class Company
{
[Key]
public int ID { get; set; }
public string Name { get; set; }
public string Promo { get; set; }
public virtual List<Contact> Contacts { get; set; }
}
public class Contact
{
[Key]
public int ContactID { get; set; }
[ForeignKey("Company")]
public int CompanyID { get; set; }
public virtual Company Company { get; set; }
public string ContactName { get; set; }
public string ContactNumber { get; set; }
}
Here's the controller's index() method:
// GET: Companies
public async Task<IActionResult> Index()
{
List<Company> viewModelData = await _context.Companies
.Include(c => c.Contacts)
.ToListAsync();
return View(viewModelData);
}
Edit method:
// GET: Companies/Edit/5
public async Task<IActionResult> Edit(int? id)
{
if (id == null)
{
return NotFound();
}
var company = await _context.Companies
.Include(v => v.Contacts)
.FirstOrDefaultAsync(m => m.ID == id);
if (company == null)
{
return NotFound();
}
return View(company);
}
// POST: Companies/Edit/5
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Edit(int? id, [Bind("ID,Name,Promo,Contacts")] Company company)
{
if (id == null)
{
return NotFound();
}
var companyToUpdate = await _context.Companies
.Include(v => v.Contacts)
.FirstOrDefaultAsync(m => m.ID == id);
if (await TryUpdateModelAsync<Company>(
companyToUpdate,
"",
i => i.Name, i => i.Promo, i => i.Contacts
)) {
try
{
await _context.SaveChangesAsync();
}
catch (DbUpdateException /* ex */)
{
//Log the error (uncomment ex variable name and write a log.)
ModelState.AddModelError("", "Unable to save changes. " +
"Try again, and if the problem persists, " +
"see your system administrator.");
}
return RedirectToAction("Index");
}
return View(companyToUpdate);
}
This is not correct since the code only allows me to edit Company info. How do I modify the code so that I can edit both Company & its contacts on the same edit view?
If you're purely looking to update values, then you can explicitly update them like so. A View Model is also recommended but this comes down to good vs bad practice. This omits the exception handling and serves only as an example of how to map these values, you'll have to modify the remainder of your controller to work directly with the CompanyEditViewModel
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Edit(int? id, [Bind("ID,Name,Promo,Contacts")] CompanyEditViewModel company)
{
if (!ModelState.IsValid)
return RedirectToAction("Index");
var companyToUpdate = await _context.Companies
.Include(v => v.Contacts)
.FirstOrDefaultAsync(m => m.ID == id);
// Assign the new values
companyToUpdate.Name = company.Name;
companyToUpdate.Promo = company.Promo;
companyToUpdate.Contacts = company.Contacts?.ToList();
// Update and save
_context.Companies.Update(companyToUpdate);
await _context.SaveChangesAsync();
return View(companyToUpdate);
}
public class Company
{
public int ID { get; set; }
public string Name { get; set; }
public string Promo { get; set; } // Yes or No field
public List<Contact> Contacts { get; set; }
public class Contact
{
[Key]
public int ContactID { get; set; }
public int CompanyID { get; set; }
public string ContactName { get; set; }
public string ContactNumber { get; set; }
}
}
// The View Model contains the Company details which were modified
// The first Edit method will have to be updated to bind this View Model to the view
public class CompanyEditViewModel
{
public int ID { get; set; }
public string Name { get; set; }
public string Promo { get; set; }
public IList<Company.Contact> Contacts { get; set; }
}
I have this scenario:
public class Member
{
public int MemberID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public virtual ICollection<Comment> Comments { get; set; }
}
public class Comment
{
public int CommentID { get; set; }
public string Message { get; set; }
public virtual ICollection<Member> Members { get; set; }
}
public class MemberComment
{
public int MemberID { get; set; }
public int CommentID { get; set; }
public int Something { get; set; }
public string SomethingElse { get; set; }
}
How do I configure my association with fluent API? Or is there a better way to create the association table?
It's not possible to create a many-to-many relationship with a customized join table. In a many-to-many relationship EF manages the join table internally and hidden. It's a table without an Entity class in your model. To work with such a join table with additional properties you will have to create actually two one-to-many relationships. It could look like this:
public class Member
{
public int MemberID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public virtual ICollection<MemberComment> MemberComments { get; set; }
}
public class Comment
{
public int CommentID { get; set; }
public string Message { get; set; }
public virtual ICollection<MemberComment> MemberComments { get; set; }
}
public class MemberComment
{
[Key, Column(Order = 0)]
public int MemberID { get; set; }
[Key, Column(Order = 1)]
public int CommentID { get; set; }
public virtual Member Member { get; set; }
public virtual Comment Comment { get; set; }
public int Something { get; set; }
public string SomethingElse { get; set; }
}
If you now want to find all comments of members with LastName = "Smith" for example you can write a query like this:
var commentsOfMembers = context.Members
.Where(m => m.LastName == "Smith")
.SelectMany(m => m.MemberComments.Select(mc => mc.Comment))
.ToList();
... or ...
var commentsOfMembers = context.MemberComments
.Where(mc => mc.Member.LastName == "Smith")
.Select(mc => mc.Comment)
.ToList();
Or to create a list of members with name "Smith" (we assume there is more than one) along with their comments you can use a projection:
var membersWithComments = context.Members
.Where(m => m.LastName == "Smith")
.Select(m => new
{
Member = m,
Comments = m.MemberComments.Select(mc => mc.Comment)
})
.ToList();
If you want to find all comments of a member with MemberId = 1:
var commentsOfMember = context.MemberComments
.Where(mc => mc.MemberId == 1)
.Select(mc => mc.Comment)
.ToList();
Now you can also filter by the properties in your join table (which would not be possible in a many-to-many relationship), for example: Filter all comments of member 1 which have a 99 in property Something:
var filteredCommentsOfMember = context.MemberComments
.Where(mc => mc.MemberId == 1 && mc.Something == 99)
.Select(mc => mc.Comment)
.ToList();
Because of lazy loading things might become easier. If you have a loaded Member you should be able to get the comments without an explicit query:
var commentsOfMember = member.MemberComments.Select(mc => mc.Comment);
I guess that lazy loading will fetch the comments automatically behind the scenes.
Edit
Just for fun a few examples more how to add entities and relationships and how to delete them in this model:
1) Create one member and two comments of this member:
var member1 = new Member { FirstName = "Pete" };
var comment1 = new Comment { Message = "Good morning!" };
var comment2 = new Comment { Message = "Good evening!" };
var memberComment1 = new MemberComment { Member = member1, Comment = comment1,
Something = 101 };
var memberComment2 = new MemberComment { Member = member1, Comment = comment2,
Something = 102 };
context.MemberComments.Add(memberComment1); // will also add member1 and comment1
context.MemberComments.Add(memberComment2); // will also add comment2
context.SaveChanges();
2) Add a third comment of member1:
var member1 = context.Members.Where(m => m.FirstName == "Pete")
.SingleOrDefault();
if (member1 != null)
{
var comment3 = new Comment { Message = "Good night!" };
var memberComment3 = new MemberComment { Member = member1,
Comment = comment3,
Something = 103 };
context.MemberComments.Add(memberComment3); // will also add comment3
context.SaveChanges();
}
3) Create new member and relate it to the existing comment2:
var comment2 = context.Comments.Where(c => c.Message == "Good evening!")
.SingleOrDefault();
if (comment2 != null)
{
var member2 = new Member { FirstName = "Paul" };
var memberComment4 = new MemberComment { Member = member2,
Comment = comment2,
Something = 201 };
context.MemberComments.Add(memberComment4);
context.SaveChanges();
}
4) Create relationship between existing member2 and comment3:
var member2 = context.Members.Where(m => m.FirstName == "Paul")
.SingleOrDefault();
var comment3 = context.Comments.Where(c => c.Message == "Good night!")
.SingleOrDefault();
if (member2 != null && comment3 != null)
{
var memberComment5 = new MemberComment { Member = member2,
Comment = comment3,
Something = 202 };
context.MemberComments.Add(memberComment5);
context.SaveChanges();
}
5) Delete this relationship again:
var memberComment5 = context.MemberComments
.Where(mc => mc.Member.FirstName == "Paul"
&& mc.Comment.Message == "Good night!")
.SingleOrDefault();
if (memberComment5 != null)
{
context.MemberComments.Remove(memberComment5);
context.SaveChanges();
}
6) Delete member1 and all its relationships to the comments:
var member1 = context.Members.Where(m => m.FirstName == "Pete")
.SingleOrDefault();
if (member1 != null)
{
context.Members.Remove(member1);
context.SaveChanges();
}
This deletes the relationships in MemberComments too because the one-to-many relationships between Member and MemberComments and between Comment and MemberComments are setup with cascading delete by convention. And this is the case because MemberId and CommentId in MemberComment are detected as foreign key properties for the Member and Comment navigation properties and since the FK properties are of type non-nullable int the relationship is required which finally causes the cascading-delete-setup. Makes sense in this model, I think.
I'll just post the code to do this using the fluent API mapping.
public class User {
public int UserID { get; set; }
public string Username { get; set; }
public string Password { get; set; }
public ICollection<UserEmail> UserEmails { get; set; }
}
public class Email {
public int EmailID { get; set; }
public string Address { get; set; }
public ICollection<UserEmail> UserEmails { get; set; }
}
public class UserEmail {
public int UserID { get; set; }
public int EmailID { get; set; }
public bool IsPrimary { get; set; }
}
On your DbContext derived class you could do this:
public class MyContext : DbContext {
protected override void OnModelCreating(DbModelBuilder builder) {
// Primary keys
builder.Entity<User>().HasKey(q => q.UserID);
builder.Entity<Email>().HasKey(q => q.EmailID);
builder.Entity<UserEmail>().HasKey(q =>
new {
q.UserID, q.EmailID
});
// Relationships
builder.Entity<UserEmail>()
.HasRequired(t => t.Email)
.WithMany(t => t.UserEmails)
.HasForeignKey(t => t.EmailID)
builder.Entity<UserEmail>()
.HasRequired(t => t.User)
.WithMany(t => t.UserEmails)
.HasForeignKey(t => t.UserID)
}
}
It has the same effect as the accepted answer, with a different approach, which is no better nor worse.
The code provided by this answer is right, but incomplete, I've tested it. There are missing properties in "UserEmail" class:
public UserTest UserTest { get; set; }
public EmailTest EmailTest { get; set; }
I post the code I've tested if someone is interested.
Regards
using System.Data.Entity;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Linq;
using System.Web;
#region example2
public class UserTest
{
public int UserTestID { get; set; }
public string UserTestname { get; set; }
public string Password { get; set; }
public ICollection<UserTestEmailTest> UserTestEmailTests { get; set; }
public static void DoSomeTest(ApplicationDbContext context)
{
for (int i = 0; i < 5; i++)
{
var user = context.UserTest.Add(new UserTest() { UserTestname = "Test" + i });
var address = context.EmailTest.Add(new EmailTest() { Address = "address#" + i });
}
context.SaveChanges();
foreach (var user in context.UserTest.Include(t => t.UserTestEmailTests))
{
foreach (var address in context.EmailTest)
{
user.UserTestEmailTests.Add(new UserTestEmailTest() { UserTest = user, EmailTest = address, n1 = user.UserTestID, n2 = address.EmailTestID });
}
}
context.SaveChanges();
}
}
public class EmailTest
{
public int EmailTestID { get; set; }
public string Address { get; set; }
public ICollection<UserTestEmailTest> UserTestEmailTests { get; set; }
}
public class UserTestEmailTest
{
public int UserTestID { get; set; }
public UserTest UserTest { get; set; }
public int EmailTestID { get; set; }
public EmailTest EmailTest { get; set; }
public int n1 { get; set; }
public int n2 { get; set; }
//Call this code from ApplicationDbContext.ConfigureMapping
//and add this lines as well:
//public System.Data.Entity.DbSet<yournamespace.UserTest> UserTest { get; set; }
//public System.Data.Entity.DbSet<yournamespace.EmailTest> EmailTest { get; set; }
internal static void RelateFluent(System.Data.Entity.DbModelBuilder builder)
{
// Primary keys
builder.Entity<UserTest>().HasKey(q => q.UserTestID);
builder.Entity<EmailTest>().HasKey(q => q.EmailTestID);
builder.Entity<UserTestEmailTest>().HasKey(q =>
new
{
q.UserTestID,
q.EmailTestID
});
// Relationships
builder.Entity<UserTestEmailTest>()
.HasRequired(t => t.EmailTest)
.WithMany(t => t.UserTestEmailTests)
.HasForeignKey(t => t.EmailTestID);
builder.Entity<UserTestEmailTest>()
.HasRequired(t => t.UserTest)
.WithMany(t => t.UserTestEmailTests)
.HasForeignKey(t => t.UserTestID);
}
}
#endregion
I want to propose a solution where both flavors of a many-to-many configuration can be achieved.
The "catch" is we need to create a view that targets the Join Table, since EF validates that a schema's table may be mapped at most once per EntitySet.
This answer adds to what's already been said in previous answers and doesn't override any of those approaches, it builds upon them.
The model:
public class Member
{
public int MemberID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public virtual ICollection<Comment> Comments { get; set; }
public virtual ICollection<MemberCommentView> MemberComments { get; set; }
}
public class Comment
{
public int CommentID { get; set; }
public string Message { get; set; }
public virtual ICollection<Member> Members { get; set; }
public virtual ICollection<MemberCommentView> MemberComments { get; set; }
}
public class MemberCommentView
{
public int MemberID { get; set; }
public int CommentID { get; set; }
public int Something { get; set; }
public string SomethingElse { get; set; }
public virtual Member Member { get; set; }
public virtual Comment Comment { get; set; }
}
The configuration:
using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity.ModelConfiguration;
public class MemberConfiguration : EntityTypeConfiguration<Member>
{
public MemberConfiguration()
{
HasKey(x => x.MemberID);
Property(x => x.MemberID).HasColumnType("int").IsRequired();
Property(x => x.FirstName).HasColumnType("varchar(512)");
Property(x => x.LastName).HasColumnType("varchar(512)")
// configure many-to-many through internal EF EntitySet
HasMany(s => s.Comments)
.WithMany(c => c.Members)
.Map(cs =>
{
cs.ToTable("MemberComment");
cs.MapLeftKey("MemberID");
cs.MapRightKey("CommentID");
});
}
}
public class CommentConfiguration : EntityTypeConfiguration<Comment>
{
public CommentConfiguration()
{
HasKey(x => x.CommentID);
Property(x => x.CommentID).HasColumnType("int").IsRequired();
Property(x => x.Message).HasColumnType("varchar(max)");
}
}
public class MemberCommentViewConfiguration : EntityTypeConfiguration<MemberCommentView>
{
public MemberCommentViewConfiguration()
{
ToTable("MemberCommentView");
HasKey(x => new { x.MemberID, x.CommentID });
Property(x => x.MemberID).HasColumnType("int").IsRequired();
Property(x => x.CommentID).HasColumnType("int").IsRequired();
Property(x => x.Something).HasColumnType("int");
Property(x => x.SomethingElse).HasColumnType("varchar(max)");
// configure one-to-many targeting the Join Table view
// making all of its properties available
HasRequired(a => a.Member).WithMany(b => b.MemberComments);
HasRequired(a => a.Comment).WithMany(b => b.MemberComments);
}
}
The context:
using System.Data.Entity;
public class MyContext : DbContext
{
public DbSet<Member> Members { get; set; }
public DbSet<Comment> Comments { get; set; }
public DbSet<MemberCommentView> MemberComments { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Configurations.Add(new MemberConfiguration());
modelBuilder.Configurations.Add(new CommentConfiguration());
modelBuilder.Configurations.Add(new MemberCommentViewConfiguration());
OnModelCreatingPartial(modelBuilder);
}
}
From Saluma's (#Saluma) answer
If you now want to find all comments of members with LastName =
"Smith" for example you can write a query like this:
This still works...
var commentsOfMembers = context.Members
.Where(m => m.LastName == "Smith")
.SelectMany(m => m.MemberComments.Select(mc => mc.Comment))
.ToList();
...but could now also be...
var commentsOfMembers = context.Members
.Where(m => m.LastName == "Smith")
.SelectMany(m => m.Comments)
.ToList();
Or to create a list of members with the name "Smith" (we assume there is
more than one) along with their comments you can use a projection:
This still works...
var membersWithComments = context.Members
.Where(m => m.LastName == "Smith")
.Select(m => new
{
Member = m,
Comments = m.MemberComments.Select(mc => mc.Comment)
})
.ToList();
...but could now also be...
var membersWithComments = context.Members
.Where(m => m.LastName == "Smith")
.Select(m => new
{
Member = m,
m.Comments
})
.ToList();
If you want to remove a comment from a member
var comment = ... // assume comment from member John Smith
var member = ... // assume member John Smith
member.Comments.Remove(comment);
If you want to Include() a member's comments
var member = context.Members
.Where(m => m.FirstName == "John", m.LastName == "Smith")
.Include(m => m.Comments);
This all feels like syntactic sugar, however, it does get you a few perks if you're willing to go through the additional configuration. Either way, you seem to be able to get the best of both approaches.
I've come back here a couple times now, but it seems that EF Core has done a few updates in the past decade, so here's where I'm at currently with setting up many-to-many with custom join entity:
public class MemberModel
{
public int MemberId { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public ICollection<CommentModel> Comments { get; set; }
}
public class CommentModel
{
public int CommentId { get; set; }
public string Message { get; set; }
public ICollection<MemberModel> Members { get; set; }
}
public class MemberCommentModel
{
public int Something { get; set; }
public string SomethingElse { get; set; }
public int MembersId { get; set; }
[ForeignKey("MembersId")]
public MemberModel Member { get; set; }
public int CommentsId { get; set; }
[ForeignKey("CommentsId")]
public CommentModel Comment { get; set; }
}
Then in your OnModelCreating:
//Allows access directly from Comments or Members entities to the other
builder.Entity<MemberModel>()
.HasMany(x => x.Comments)
.WithMany(x => x.Members)
.UsingEntity<MemberCommentModel>();
//Defines the actual relationships for the middle table
builder.Entity<MemberCommentModel>()
.HasOne(x => x.Comment)
.WithOne()
.OnDelete(DeleteBehavior.NoAction);
builder.Entity<MemberCommentModel>()
.HasOne(x => x.Member)
.WithOne()
.OnDelete(DeleteBehavior.NoAction);
TLDR; (semi-related to an EF editor bug in EF6/VS2012U5) if you generate the model from DB and you cannot see the attributed m:m table: Delete the two related tables -> Save .edmx -> Generate/add from database -> Save.
For those who came here wondering how to get a many-to-many relationship with attribute columns to show in the EF .edmx file (as it would currently not show and be treated as a set of navigational properties), AND you generated these classes from your database table (or database-first in MS lingo, I believe.)
Delete the 2 tables in question (to take the OP example, Member and Comment) in your .edmx and add them again through 'Generate model from database'. (i.e. do not attempt to let Visual Studio update them - delete, save, add, save)
It will then create a 3rd table in line with what is suggested here.
This is relevant in cases where a pure many-to-many relationship is added at first, and the attributes are designed in the DB later.
This was not immediately clear from this thread/Googling. So just putting it out there as this is link #1 on Google looking for the issue but coming from the DB side first.
One way to solve this error is to put the ForeignKey attribute on top of the property you want as a foreign key and add the navigation property.
Note: In the ForeignKey attribute, between parentheses and double quotes, place the name of the class referred to in this way.