From Json convert Generic List to DataSet in C#

First of all, when working with conversions of such structures, you need to "parse" the JSON to a class or a list of classes. Second, only when you have the JSON "parsed" with a class or list, you proceed to make the transformation.

The question caught my attention, since it plays with Generics and Reflection to achieve the requested functionality.

Since I didn't know the data type values, I put in a simple class (IndividualElement) with pure string properties and an additional class generated courtesy of Mockaroo .

Without further details to add, to the code:

using System;
using System.Collections.Generic;
using System.Data;

namespace ConsoleApp
{
    public static class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");

            var json = @"[{""CO_EMPR"":""18"",""TI_REQI"":""RAL"",""NU_REQI"":""0001-0000000049"",""SECUENCIA"":""4"",""CODIGO_ITEM"":""600101008"",""CANTIDAD_SOLICITADA"":""5""},{""CO_EMPR"":""18"",""TI_REQI"":""RAL"",""NU_REQI"":""0001-0000000049"",""SECUENCIA"":""5"",""CODIGO_ITEM"":""600401036"",""CANTIDAD_SOLICITADA"":""5""}]";

            List<ElementoIndividual> miListaGenerica = Newtonsoft.Json.JsonConvert.DeserializeObject<List<ElementoIndividual>>(json);
            var resultadoDataSet = CrearDataSet(miListaGenerica);

            Console.WriteLine(resultadoDataSet.GetXml());

            var json2 = @"[{ ""id"":1,""first_name"":""Sharleen"",""last_name"":""Carbry"",""email"":""[email protected]"",""phone"":""286-408-8677"",""random"":3},{ ""id"":2,""first_name"":""Holli"",""last_name"":""Fearns"",""email"":""[email protected]"",""phone"":""448-956-6372"",""random"":22},{ ""id"":3,""first_name"":""Marabel"",""last_name"":""Millichip"",""email"":""[email protected]"",""phone"":""458-601-0766"",""random"":80}]";

            List<Mockaroo> miListaGenerica2 = Newtonsoft.Json.JsonConvert.DeserializeObject<List<Mockaroo>>(json2);
            var resultado2 = CrearDataSet(miListaGenerica2);
            Console.WriteLine(resultado2.GetXml());

            Console.ReadLine();

        }

        public static DataSet CrearDataSet<T>(this IList<T> list)
        {
            Type elementType = typeof(T);
            DataSet ds = new DataSet();
            DataTable t = new DataTable();
            ds.Tables.Add(t);

            //Agregar una columna a la tabla para cada propiedad pública en T
            foreach (var propInfo in elementType.GetProperties())
            {
                //ColType = Column Type = Tipo de dato que hay en la columna
                Type ColType = Nullable.GetUnderlyingType(propInfo.PropertyType) ?? propInfo.PropertyType;

                t.Columns.Add(propInfo.Name, ColType);
            }

            //Recorrer cada propiedad en T y añadir cada valor a la tabla
            foreach (T item in list)
            {
                DataRow row = t.NewRow();

                foreach (var propInfo in elementType.GetProperties())
                {
                    row[propInfo.Name] = propInfo.GetValue(item, null) ?? DBNull.Value;
                }

                t.Rows.Add(row);
            }

            return ds;
        }
    }


    public class ElementoIndividual
    {
        public string CO_EMPR { get; set; }
        public string TI_REQI { get; set; }
        public string NU_REQI { get; set; }
        public string SECUENCIA { get; set; }
        public string CODIGO_ITEM { get; set; }
        public string CANTIDAD_SOLICITADA { get; set; }
    }

    public class Mockaroo
    {
        public int id { get; set; }
        public string first_name { get; set; }
        public string last_name { get; set; }
        public string email { get; set; }
        public string phone { get; set; }
        public int random { get; set; }
    }

}

And here we have what is generated by GetXML()

<NewDataSet>
  <Table1>
    <CO_EMPR>18</CO_EMPR>
    <TI_REQI>RAL</TI_REQI>
    <NU_REQI>0001-0000000049</NU_REQI>
    <SECUENCIA>4</SECUENCIA>
    <CODIGO_ITEM>600101008</CODIGO_ITEM>
    <CANTIDAD_SOLICITADA>5</CANTIDAD_SOLICITADA>
  </Table1>
  <Table1>
    <CO_EMPR>18</CO_EMPR>
    <TI_REQI>RAL</TI_REQI>
    <NU_REQI>0001-0000000049</NU_REQI>
    <SECUENCIA>5</SECUENCIA>
    <CODIGO_ITEM>600401036</CODIGO_ITEM>
    <CANTIDAD_SOLICITADA>5</CANTIDAD_SOLICITADA>
  </Table1>
</NewDataSet>
<NewDataSet>
  <Table1>
    <id>1</id>
    <first_name>Sharleen</first_name>
    <last_name>Carbry</last_name>
    <email>[email protected]</email>
    <phone>286-408-8677</phone>
    <random>3</random>
  </Table1>
  <Table1>
    <id>2</id>
    <first_name>Holli</first_name>
    <last_name>Fearns</last_name>
    <email>[email protected]</email>
    <phone>448-956-6372</phone>
    <random>22</random>
  </Table1>
  <Table1>
    <id>3</id>
    <first_name>Marabel</first_name>
    <last_name>Millichip</last_name>
    <email>[email protected]</email>
    <phone>458-601-0766</phone>
    <random>80</random>
  </Table1>
</NewDataSet>