https://stackoverflow.com/questions/66782290

CSharp · Console

/Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using Newtonsoft.Json;
					
public class Program
{
	public static void Main()
	{
		// sales data
		var sellerId = "157747190185796800";
		var listToReturn = new List<SalesDataRow>
		{
			new SalesDataRow { DateFromStr = "2020-08-25", Sales = 195000, Commission = 25350 },	
			new SalesDataRow { DateFromStr = "2020-08-26", Sales = 70500, Commission = 9165 },	
			new SalesDataRow { DateFromStr = "2020-08-27", Sales = 51000, Commission = 6630 },	
		};
		
		// shape the data into the structure we want for the JSON
		var resultToReturn = new 
		{
			sellerId,
			data = listToReturn.ToDictionary (
				item => item.DateFromStr,
				item => new 
				{ 
					sales = item.Sales, 
					commission = item.Commission 
				}
			)
		};
		
		// serialize
		var json = JsonConvert.SerializeObject(resultToReturn, Formatting.Indented);
		
		Console.WriteLine(json);
	}
	
	
}

class SalesDataRow
{
	public string DateFromStr { get; set; }
	public int Sales { get; set; }
	public int Commission { get; set; }
}