I am learning ASP.NET MVC 5 and EF. I want each registered user to be able to create a simple list of their belonging items.
So I have an Item class in Model folder:
class Item
{
public int Id {get; set;}
public string Name {get; set;}
}
How can I update my database using code first approach so that user can have a foreign key to Items table so that I can query all items that belong to the current user?
Select *
From Items
Where userID = currentUserID
You will need to have item as a separate entity(Model) then create a relationship with the user. When you use this approach EF will create respective tables with their relationships(one to many i.e one user can have many entities).
Here is how its implemented in code.
Item Class
public class Item
{
public int Id {get; set;}
public string Name {get; set;}
//foreign key
public int UserId {get; set;}
//Navigation property
public virtual ApplicationUser User{get; set;}
}
Application user class
public class ApplicationUser : IdentityUser
{
//Here you can add more properties if you wish to
public string FirstName{ get; set; }
public string LastName { get; set; }
//User-Item relationship (user can have many Items)
public virtual List<Item> Items { get; set; }
}
Then you will have to go to ApplicationDbContext and add DbSet of Item as below
public class ApplicationDbContext : IdentityDbContext<SchedulerUser>
{
public virtual DbSet<Item> Items { get; set; }
//some code are excluded for clarity
}
To get the list of all items that belong to the user you can query using linq like
var _db = new ApplicationDbContext();
var Items = _db.Users.Find(UserId).Items.ToList();
