C# coding to obtain the data in mysql

hai
i am a student working on the project of obtaining the data fro the msql database,i tried to write the code in c# for windows application but i receive some errors in that so please help me with those errors

code is

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace WindowsFormsApplication9
{
    public partial class Form1 : Form
    {
        //SqlConnection con = new SqlConnection( "server=localhost;user id=root;password=******;database=test");//
        SqlConnection con = new SqlConnection();

        public Form1()
        {
            InitializeComponent();
        }


        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
               // con.ConnectionString = "server=localhost;user id=root;password=*****;database=test";

                con.ConnectionString = "server=.\\sqlexpress;database=test;integrated security=true;";

                SqlDataAdapter adp = new SqlDataAdapter("SELECT Date_time,CT1_AH,CT2_AH,CT3_AH,CT1_WattHr,CT2_WattHr,Max_Temperature,Min_Temperature,Volt1,Amp1,Volt2,Batt1_percentFull,Batt1_gotcharged,Batt2_percentFull,Batt2_gotcharged FROM periodicdata WHERE Date_time BETWEEN '" + dateTimePicker1.Value.ToShortDateString() + "' AND '" + dateTimePicker2.Value.ToShortDateString() + "'", con);
                DataSet ds = new DataSet();
                adp.Fill(ds, "s");
                if (ds.Tables["s"].Rows.Count > 0)
                {
                    for (int i = 0; i < ds.Tables["s"].Rows.Count; i++)
                    {
                        dataGridView1.Rows.Add();
                        dataGridView1.Rows[i].Cells[0].Value = ds.Tables["s"].Rows[i].ItemArray[0];
                        dataGridView1.Rows[i].Cells[1].Value = ds.Tables["s"].Rows[i].ItemArray[1];
                        dataGridView1.Rows[i].Cells[2].Value = ds.Tables["s"].Rows[i].ItemArray[2];
                        dataGridView1.Rows[i].Cells[3].Value = ds.Tables["s"].Rows[i].ItemArray[3];
                        dataGridView1.Rows[i].Cells[4].Value = ds.Tables["s"].Rows[i].ItemArray[4];
                        dataGridView1.Rows[i].Cells[5].Value = ds.Tables["s"].Rows[i].ItemArray[5];
                        dataGridView1.Rows[i].Cells[6].Value = ds.Tables["s"].Rows[i].ItemArray[6];
                        dataGridView1.Rows[i].Cells[7].Value = ds.Tables["s"].Rows[i].ItemArray[7];
                        dataGridView1.Rows[i].Cells[8].Value = ds.Tables["s"].Rows[i].ItemArray[8];
                        dataGridView1.Rows[i].Cells[9].Value = ds.Tables["s"].Rows[i].ItemArray[9];
                        dataGridView1.Rows[i].Cells[10].Value = ds.Tables["s"].Rows[i].ItemArray[10];
                        dataGridView1.Rows[i].Cells[11].Value = ds.Tables["s"].Rows[i].ItemArray[11];
                        dataGridView1.Rows[i].Cells[12].Value = ds.Tables["s"].Rows[i].ItemArray[12];
                        dataGridView1.Rows[i].Cells[13].Value = ds.Tables["s"].Rows[i].ItemArray[13];
                        dataGridView1.Rows[i].Cells[14].Value = ds.Tables["s"].Rows[i].ItemArray[14];
                    }
                }
                else
                {
                    MessageBox.Show("No Record Found For Given Date.");
                }
            }
            catch (Exception ex) { MessageBox.Show(ex.ToString()); }
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            dataGridView1.Columns.Add("", "Date Time");
            dataGridView1.Columns.Add("", "CT1_AH");
            dataGridView1.Columns.Add("", "CT2_AH");
            dataGridView1.Columns.Add("", "CT3_AH");
            dataGridView1.Columns.Add("", "CT1_WattHr");
            dataGridView1.Columns.Add("", "CT2_WattHr");
            dataGridView1.Columns.Add("", "Max_Temperature");
            dataGridView1.Columns.Add("", "Min_Temperature");
            dataGridView1.Columns.Add("", "Volt1");
            dataGridView1.Columns.Add("", "Amp1");
            dataGridView1.Columns.Add("", "Volt2");
            dataGridView1.Columns.Add("", "Batt1_percentFull");
            dataGridView1.Columns.Add("", "Batt1_gotCharged");
            dataGridView1.Columns.Add("", "Batt2_percentFull");
            dataGridView1.Columns.Add("", "Batt2_gotCharged");

            ChangeDateFormat(dateTimePicker1);
            ChangeDateFormat(dateTimePicker2);
        }

        public void ChangeDateFormat(DateTimePicker dtp)
        {
            dtp.Format = DateTimePickerFormat.Custom;
            dtp.CustomFormat = "MM/dd/yyyy";
        }

        private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {

        }

    }
}

and the error i receive is

system.InvalidOperationException: The ConnectionString property has not been initialized.
at System.Data.SqlClient.SqlConnectionFactory.PermissionDemand()
at
System.Data.SqlClient.SqlConnectionFactory.permissionDemand(DbConnectionouterConnection)
at
System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnectionouterConnection,DbConnectionFactory connectionFactory)
at System.Data.SqlClient.SqlConnection.Open()
at WindowsFormsApplication9.Form1.button1_Click(Object sender, EventArgse) in
D:\WindowsFormsApplication9\Form1.cs:line29

Tags: C#, MySQL