Linq Group by Complex Object (E.G list element of object)

Question

I have an object like below;

var json = @"{
  'TableNumber': '3',
  'TableId': '81872d39-9480-4d2d-abfc-b8e4f33a43b6',
  'tableMenuItems': [
    {
      'Id': '4664a2d3-c0af-443d-8af5-2bd21e71838b',
      'Name': 'Bonfile',
      'tableMenuItemCondiment': [
        {
          'Id': '9b1f01a0-0313-46b6-b7f1-003c0e846136',
          'Name': 'Kekikkli',
          'Price': 0
        },
        {
          'Id': '38a9cce6-f20c-4f78-b6c9-c15e79ecc8f1',
          'Name': 'mayonez',
          'Price': 0
        },
        {
          'Id': 'cb3a7811-668b-4e45-bce3-e6b2b13af9e1',
          'Name': 'Rare',
          'Price': 0
        }
      ],
      'Price': 45,
      'Count': 1
    },
    {
      'Id': '4664a2d3-c0af-443d-8af5-2bd21e71838b',
      'Name': 'Bonfile',
      'tableMenuItemCondiment': [
        {
          'Id': 'c3c62f7d-987d-4523-849c-932334db4e4f',
          'Name': 'Kekikkli',
          'Price': 0
        },
        {
          'Id': 'cbb16028-6e77-4e4b-a1c9-d969e804f093',
          'Name': 'mayonez',
          'Price': 0
        },
        {
          'Id': '16f9efc2-73d3-4a09-87fc-e1fb76957ed2',
          'Name': 'Rare',
          'Price': 0
        }
      ],
      'Price': 45,
      'Count': 1
    }
  ],
  'TotalPrice': 90
}";

As you see above, the object has element of list as tableMenuItems. There are two object in tableMenuItems property and this are completly identical. I want to group this object like below;

var json = @"{
  'TableNumber': '3',
  'TableId': '81872d39-9480-4d2d-abfc-b8e4f33a43b6',
  'tableMenuItems': [
    {
      'Id': '4664a2d3-c0af-443d-8af5-2bd21e71838b',
      'Name': 'Bonfile',
      'tableMenuItemCondiment': [
        {
          'Id': '9b1f01a0-0313-46b6-b7f1-003c0e846136',
          'Name': 'Kekikkli',
          'Price': 0
        },
        {
          'Id': '38a9cce6-f20c-4f78-b6c9-c15e79ecc8f1',
          'Name': 'mayonez',
          'Price': 0
        },
        {
          'Id': 'cb3a7811-668b-4e45-bce3-e6b2b13af9e1',
          'Name': 'Rare',
          'Price': 0
        }
      ],
      'Price': 90,
      'Count': 2
    }    
  ],
  'TotalPrice': 90
}";

As you see if two tablemenuitems is same and their condiment is same i grouping them. I made some IEqualityComparer for gruping but it's not work what i excepted.

Here is what i did you see below link;

https://dotnetfiddle.net/QQFfIy

I don't understand what i did wrong

These fiddles will disappear in due time. Put the code in your question. — Gert Arnold, Jul 29 '20 at 09:04

score 2 · Accepted Answer · answered Jul 29 '20 at 08:33

1 ) I've created my classes to meet json,

public class MyTable {
    public string TableNumber { get; set; }
    public string TableId { get; set; }
    public List<TableMenu> tableMenuItems { get; set; }
    public int TotalPrice { get; set; }
}

public class TableMenu {
    public string Id { get; set; }
    public string Name { get; set; }
    public List<TableMenuItemCondiment> tableMenuItemCondiment { get; set; }
    public int Price { get; set; }
    public int Count { get; set; }
}

public class TableMenuItemCondiment {
    public string Id { get; set; }
    public string Name { get; set; }
    public int Price { get; set; }
}

2 ) Then i've deserialized object by NewtonSoft,

MyTable myTable = JsonConvert.DeserializeObject<MyTable>(json);

3 ) Converted object as,

MyTable result = new MyTable() {
                TableNumber = myTable.TableNumber,
                TableId = myTable.TableId,
                tableMenuItems = myTable.tableMenuItems.GroupBy(x => x.Id).Select(x => new TableMenu() {
                    Id = x.Key,
                    Name = x.First()?.Name,
                    tableMenuItemCondiment = x.SelectMany(a=>a.tableMenuItemCondiment).GroupBy(z => z.Name).Select(z => new TableMenuItemCondiment() {
                        Id = z.First()?.Id,
                        Name = z.Key,
                        Price = z.Sum(t => t.Price)
                    }).ToList(),
                    Price = x.Sum(t => t.Price),
                    Count = x.Sum(t => t.Count)
                }).ToList(),
                TotalPrice = myTable.TotalPrice
            };

4 ) Finally serialized object to see whether it gives the response as you want,

string output = JsonConvert.SerializeObject(result);

5 ) Print the output,

Console.WriteLine(output);
Console.ReadKey();

Output:

{  "TableNumber":"3", 
  "TableId":"81872d39-9480-4d2d-abfc-b8e4f33a43b6", 
  "tableMenuItems":[
     {
        "Id":"4664a2d3-c0af-443d-8af5-2bd21e71838b",
        "Name":"Bonfile",
        "tableMenuItemCondiment":[
           {
              "Id":"9b1f01a0-0313-46b6-b7f1-003c0e846136",
              "Name":"Kekikkli",
              "Price":0
           },
           {
              "Id":"38a9cce6-f20c-4f78-b6c9-c15e79ecc8f1",
              "Name":"mayonez",
              "Price":0
           },
           {
              "Id":"cb3a7811-668b-4e45-bce3-e6b2b13af9e1",
              "Name":"Rare",
              "Price":0
           }
        ],
        "Price":90,
        "Count":2
     }    
],    
"TotalPrice":90 }

Since assuming all properties are a composite key of objects doesn't make sense, i move assuming ids and names unique for objects according to output you want. — Furkan Öztürk, Jul 29 '20 at 08:41
This options is good if all item has same number of condiments. But if two same Id and name menu item has different size of condiments then it grouping wrong. But thanks by the way, i tried to solve this problem with helping of iequalitycomparer and its work. If you want i can share it with you by the way — Cemal, Jul 29 '20 at 09:56

Linq Group by Complex Object (E.G list element of object)

1 Answers1