Friday 24 April 2015

How to convert a DataTable into JSON format in c# asp.net ?

Here I am writing a c# program that will convert a DataTable into JSON formate. First I created a DataTable and then inserted 5 Rows into it, then passed to a method ConvertDataTableToJSON(DataTable dt) and it will return a JSON string.

Source code:-

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml;
using System.IO;
using System.Data;
using System.Globalization;
using Newtonsoft.Json;

namespace ConsoleDemoApp
{
    class ConvertDataTableToJSON
    {

     protected void Page_Load(object sender, EventArgs e)
     {
         try{
                // Create datatable first
               DataTable dt= GetTable();
                // Convert it into JSON formate.
             String jsonString=  ConvertDataTableToJson(dt);

               }
            catch(Exception ex)
            {
                //catch the exception and write to txt file
                writeInFile(ex.ToString());
            }
      }

// Create DataTable and insert some rows.
       protected DataTable GetTable()
        {
            // Here we create a DataTable with four columns.
            DataTable table = new DataTable();
            table.Columns.Add("Id", typeof(int));
            table.Columns.Add("Name", typeof(string));
            table.Columns.Add("Gender", typeof(string));
            table.Columns.Add("Email", typeof(DateTime));

            // Here we add five DataRows.
            table.Rows.Add(1, "Ram", "Male", "abc@gmail.com");
            table.Rows.Add(2, "Shyam", "Male", "abc@gmail.com");
            table.Rows.Add(3, "Kavita", "Female","abc@gmail.com");
            table.Rows.Add(4, "Suman", "Female", "abc@gmail.com");
            table.Rows.Add(4, "Naveen", "Male","abc@gmail.com");

            return table;
        }

   // Method to convert.
        protected string ConvertDataTableToJson(DataTable dt)
        {
            System.Web.Script.Serialization.JavaScriptSerializer JSSerializer = new
            System.Web.Script.Serialization.JavaScriptSerializer();

            List<Dictionary<string, object>> DtRows =
              new List<Dictionary<string, object>>();
            Dictionary<string, object> newrow = null;

            //Code to loop each row in the datatable and add it to the dictionary object
            foreach (DataRow drow in dt.Rows)
            {
                newrow = new Dictionary<string, object>();
                foreach (DataColumn col in dt.Columns)
                {
                    newrow.Add(col.ColumnName.Trim(), drow[col]);
                }
                DtRows.Add(newrow);
            }

            //Serialising the dictionary object to produce json output

            JSSerializer.MaxJsonLength = Int32.MaxValue;

            return JSSerializer.Serialize(DtRows);
        }


   // Write exception to text file
        static void writeInFile(string excep)
        {
            // it will get base directory path but you can change it.
            string path = AppDomain.CurrentDomain.BaseDirectory;
            String dir = Path.GetDirectoryName(path);
            dir += "\\Error\\";
            if (!Directory.Exists(dir))
            {
                Directory.CreateDirectory(dir);
            }
            string newFileName = string.Format("{0:dd-MMM-yyyy_hh-mm-ss-tt}" + ".txt", DateTime.Now);
            string filepath = dir + newFileName;
            if (!File.Exists(filepath))
            {
                File.Create(filepath).Close();
            }
            using (StreamWriter w = File.AppendText(filepath))
            {
                w.WriteLine("\r\nLog Entry : ");
                w.WriteLine("{0}", DateTime.Now.ToString(CultureInfo.InvariantCulture));
                string err = "Excepation :" + excep;
                w.WriteLine(err);
                w.WriteLine("__________________________");
                w.Flush();
                w.Close();
            }
        }
  }
}


Output in JSON format


          [
             {
"Id": "1",
"Name": "Ram",
"Gender": "Male",
"Email": "abc@gmail.com",
    },
{
"Id": "2",
"Name": "Shyam",
"Gender": "Male",
"Email": "abc@gmail.com",
    },
{
"Id": "3",
"Name": "Kavita",
"Gender": "Female",
"Email": "abc@gmail.com",
    },
{
"Id": "4",
"Name": "Suman",
"Gender": "Female",
"Email": "abc@gmail.com",
    },
{
"Id": "5",
"Name": "Naveen",
"Gender": "Male",
"Email": "abc@gmail.com",
    }
]

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