将DataTable转化为json

using MySqlConnector;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MysqlConnectorDemo
{
    internal class Program
    {
        public static string GetDataFromUserTable()
        {
            string connectionString = "server=localhost;user id=root;password=***;port=3306;database=test;";
            string query = "select * from sys_user";
            using (MySqlConnection con =new MySqlConnection(connectionString))
            {
                using (MySqlCommand cmd=new MySqlCommand(query,con))
                {
                    con.Open(); 
                    MySqlDataReader reader = cmd.ExecuteReader();
                    DataTable dt=new DataTable();
                    dt.Load(reader);
                    string json = JsonConvert.SerializeObject(dt,Formatting.Indented);
                    return json;
                }
            }
        }
        static void Main(string[] args)
        {
            string json=GetDataFromUserTable();
            Console.WriteLine(json);
        }
    }
}