Styjun

I have a Project model that has a collection of AppUsers assigned to be ProjectManagers or the more general case of Users

public class Project
 
 public int ProjectID get; set; 

 [Required(ErrorMessage = " Please enter a project name")]
 public string Name get; set; 

 public virtual ICollection<AppUser> ProjectManagers get; set; 

 public virtual ICollection<AppUser> Users get; set; 
 

In my controller, I try to generate a list of all the project a particular AppUser is assigned to, regardless if they are in the ProjectManagers or Users collection

projectList = repository.Projects.Where(p => p.ProjectManagers.Contains(user) || p.Users.Contains(user));

However, if an AppUser is involved with more than one Project only the last Project populates this list. How do I ensure all associated projects are returned?

My AppUser model:

public class AppUser : IdentityUser
 
 //literally does nothing at this point and 
 // is merely a placeholder until I add more
 

In my controller I use the List action method to display all the Projects related to the AppUser. This is the part that isn't working correctly, it's only returning a single Project

public async Task<IActionResult> List(int page = 1)
 
 var user = await userManager.FindByNameAsync(User.Identity.Name);
 if(user != null)
 
 IQueryable<Project> projectList = GetUserProjects(page, user);
 var model = GetProjectsListViewModel(projectList, page, user);
 return View(model);
 
 TempData["message"] = "User not found";
 return RedirectToAction("Index", "Home");
 

The following methods are used to generate the lists and the models for pagination

 public ProjectsListViewModel GetProjectsListViewModel (IQueryable<Project> projectList, int page, AppUser user)
 
 ProjectsListViewModel model = new ProjectsListViewModel();
 model.Projects = projectList
 .OrderBy(p => p.ProjectID)
 .Skip((page - 1) * PageSize)
 .Take(PageSize);
 model.PagingInfo = new PagingInfo
 
 CurrentPage = page,
 ItemsPerPage = PageSize,
 TotalItems = projectList.Count()
 ;
 return model;
 

 public IQueryable<Project> GetUserProjects(int page, AppUser user)
 
 IQueryable<Project> projectList;
 //IQueryable<Project> result;
 if (user.UserName == "Admin")
 
 projectList = repository.Projects;
 
 else
 p.Users.Contains(user) 
 return projectList;
 

EDIT
I noticed when I run proj.ProjectManagers.Add(appUser);, it will add that user as a ProjectManager but it looks like it it also deletes them from the ProjectManager collection of any other project they were previously assigned

In here as there is no datetime in your project class, I assume that the project with bigger Id is the newer one:

var result = Projects
 .Where(p => p.ProjectManagers.Any(pm => pm.Id == user.Id)
 || p.Users.Any(u => u.Id == user.Id))
 .Select(x => new UserId = user.Id, Projects = x )
 .GroupBy(p => p.UserId)
 .Select(x => x.OrderByDescending(p => p.Projects.ProjectID).First().Project);

To get all projects of the user:

var result = Projects
 .Where(p => p.ProjectManagers.Any(pm => pm.Id == user.Id)
 || p.Users.Any(u => u.Id == user.Id));

The issue was that I wasn't using a many-to-many joint table. So when I added an AppUser to a Project, it deleted the relationship between any previous objects. Thus, only one Project would be associated with a user. To fix this, I created the class:

public class ProjectManager

 public int ProjectID get; set; 
 public Project Project get; set; 

 public string AppUserID get; set; 
 public AppUser AppUser get; set; 

and added this collection to my AppUser class:

 public class AppUser : IdentityUser
 
 public ICollection<ProjectManager> ProjectsAsManager get; set; 
 

And added the following to my dbContext:

 modelBuilder.Entity<ProjectManager>()
 .HasKey(ppm => new ppm.ProjectID, ppm.AppUserID );

 modelBuilder.Entity<ProjectManager>()
 .HasOne(pm => pm.AppUser)
 .WithMany(p => p.ProjectsAsManager)
 .HasForeignKey(pm => pm.AppUserID);

 modelBuilder.Entity<ProjectManager>()
 .HasOne(pm => pm.Project)
 .WithMany(p => p.ProjectManagers)
 .HasForeignKey(pm => pm.ProjectID);

 base.OnModelCreating(modelBuilder);

After running a migration and update, a single user can now be associated with more than one Project as a ProjectManager