C#•2y ago

EF-Core data reference [Answered]

So for school we have to make a Restaurant management system. Now I am working on Reservations with the following model

        [Key]
        public int ReservationID { get; set; }

        public string? FirstName { get; set; }

        public string? LastName { get; set; }

        public string? Adress { get; set; }

        public string? City { get; set; }

        public string? Email { get; set; }

        public int GuestsComing { get; set; }

        public DateTime? Date { get; set; }

        public TimeSpan? Time { get; set; }

        public List<Menu> ChoosenMenus { get; set; }

        public decimal FoodPrice { get; set; }

        public int UserFK { get; set; }

        [Key]
        public int ReservationID { get; set; }

        public string? FirstName { get; set; }

        public string? LastName { get; set; }

        public string? Adress { get; set; }

        public string? City { get; set; }

        public string? Email { get; set; }

        public int GuestsComing { get; set; }

        public DateTime? Date { get; set; }

        public TimeSpan? Time { get; set; }

        public List<Menu> ChoosenMenus { get; set; }

        public decimal FoodPrice { get; set; }

        public int UserFK { get; set; }

But the problem I encounter is that the list ChoosenMenus exists of Menus that are already saved in my database but when I make a post request it still tries to add the menu's This is my DbContext regarding the Reservation model so far

        modelBuilder.Entity<Reservation>()
            .HasOne<UserInfo>()
            .WithMany()
            .HasForeignKey(x => x.UserFK);

        modelBuilder.Entity<Reservation>()
            .HasOne<UserInfo>()
            .WithMany()
            .HasForeignKey(x => x.UserFK);

So I somehow need to make a reference to the already exisiting menus instead of adding them but I dont really know how to

33 Replies

Unknown User•2y ago

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Luciferno•2y ago

Yes, and save that with the Reservation

Unknown User•2y ago

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Luciferno•2y ago

Well thats it I just get a error back from swagger, one second im gonna make a screen shot of that error Huh, I have a diffrent error now give me one sec

Luciferno•2y ago

So this is the error I get. and this is the Json that im posting

{
   "ReservationID":0,
   "FirstName":"test",
   "LastName":"test",
   "Adress":"test",
   "City":"test",
   "Email":"test@test.com",
   "GuestsComing":4,
   "Date":"2022-09-18T00:00:00",
   "Time":"18:00:00",
   "ChoosenMenus":[ <--- These menus already exist in the 
      {
         "MenuId":1,
         "MenuName":"Test Menu",
         "MenuPrice":2.00,
         "TimesOrdered":3,
         "Dishes":[
            
         ]
      }
   ],
   "FoodPrice":2.00,
   "UserFK":1
}

{
   "ReservationID":0,
   "FirstName":"test",
   "LastName":"test",
   "Adress":"test",
   "City":"test",
   "Email":"test@test.com",
   "GuestsComing":4,
   "Date":"2022-09-18T00:00:00",
   "Time":"18:00:00",
   "ChoosenMenus":[ <--- These menus already exist in the 
      {
         "MenuId":1,
         "MenuName":"Test Menu",
         "MenuPrice":2.00,
         "TimesOrdered":3,
         "Dishes":[
            
         ]
      }
   ],
   "FoodPrice":2.00,
   "UserFK":1
}

Luciferno•2y ago

But if I turn off the IDENTITY_INSET option it will add that menu again to my Menus table I guess? This is my function that adds the Reservation to the DB

        public void AddReservation(Reservation reservation)
        {
            _dbContext.Reservations.Add(reservation);
            _dbContext.SaveChanges();
        }

        public void AddReservation(Reservation reservation)
        {
            _dbContext.Reservations.Add(reservation);
            _dbContext.SaveChanges();
        }

Unknown User•2y ago

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Luciferno•2y ago

Yea but i was wondering how to do that, since u cant save an property of

public int[] menuIds { get; set; }

or

public List<int> menuIds { get; set; }

public int[] menuIds { get; set; }

or

public List<int> menuIds { get; set; }

Unknown User•2y ago

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Luciferno•2y ago

Ah I see

Unknown User•2y ago

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Luciferno•2y ago

Yea true

Unknown User•2y ago

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Luciferno•2y ago

Yea we don't want that haha

Unknown User•2y ago

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Luciferno•2y ago

Nah i have blazor as front end

Unknown User•2y ago

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Luciferno•2y ago

Yea i have JWT token sorted

Unknown User•2y ago

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Luciferno•2y ago

Unknown User•2y ago

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Luciferno•2y ago

true!

Unknown User•2y ago

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MODiX•2y ago

To post C# code type the following: ```cs // code here ``` Get an example by typing $codegif in chat If your code is too long, post it to: https://paste.mod.gg/

Unknown User•2y ago

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Luciferno•2y ago

        public int ReservationID { get; set; }

        public string? FirstName { get; set; }

        public string? LastName { get; set; }

        public string? Adress { get; set; }

        public string? City { get; set; }

        public string? Email { get; set; }

        public int GuestsComing { get; set; }

        public DateTime? Date { get; set; }

        public TimeSpan? Time { get; set; }

        public List<Menu> ChoosenMenus { get; set; }

        public decimal FoodPrice { get; set; }

        public int? UserFK { get; set; }

        public int ReservationID { get; set; }

        public string? FirstName { get; set; }

        public string? LastName { get; set; }

        public string? Adress { get; set; }

        public string? City { get; set; }

        public string? Email { get; set; }

        public int GuestsComing { get; set; }

        public DateTime? Date { get; set; }

        public TimeSpan? Time { get; set; }

        public List<Menu> ChoosenMenus { get; set; }

        public decimal FoodPrice { get; set; }

        public int? UserFK { get; set; }

Unknown User•2y ago

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Luciferno•2y ago

yea that seems better

Unknown User•2y ago

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Luciferno•2y ago

Okay I will do that!

Unknown User•2y ago

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Luciferno•2y ago

Thanks 🙂

Accord•2y ago

✅ This post has been marked as answered!

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EF-Core data reference [Answered]