Hi vishalkal,

Using the below article i have created an example.

Create Line Chart (Graph) in Windows Forms Application using C# and VB.Net

Check this example. Now please take its reference and correct your code.

Namespaces

using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Windows.Forms.DataVisualization.Charting;

C#

private void Form1_Load(object sender, EventArgs e)
{
    string query = "SELECT ShipCity, COUNT(OrderId) [Total]";
    query += " FROM Orders WHERE ShipCountry = 'Brazil'";
    query += " GROUP BY ShipCity";
    DataTable dt = GetData(query);

    string[] x = (from p in dt.AsEnumerable()
                    orderby p.Field<string>("ShipCity") ascending
                    select p.Field<string>("ShipCity")).ToArray();

    int[] y = (from p in dt.AsEnumerable()
                orderby p.Field<string>("ShipCity") ascending
                select p.Field<int>("Total")).ToArray();

    Chart1.Series[0].LegendText = "Brazil Order";
    Chart1.Series[0].ChartType = SeriesChartType.Line;
    Chart1.Series[0].BorderWidth = 3;
    Chart1.Series[0].IsValueShownAsLabel = true;
    Chart1.Series[0].Points.DataBindXY(x, y);
    this.Chart1.Titles.Add("Graph Analysis");
}

private static DataTable GetData(string query)
{
    string constr = @"Data Source=.;Initial Catalog=Northwind;User ID=sa;Password=pass@123";
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlDataAdapter sda = new SqlDataAdapter(query, con))
        {
            DataTable dt = new DataTable();
            sda.Fill(dt);
            return dt;
        }
    }
}

private void Chart1_MouseMove(object sender, MouseEventArgs e)
{
    HitTestResult result = Chart1.HitTest(e.X, e.Y);
    if (result.ChartElementType == ChartElementType.DataPoint)
    {
        this.Cursor = Cursors.Hand;
        lblValue.Text = Chart1.Series[0].Points[result.PointIndex].YValues[0].ToString();
    }
    else
    {
        this.Cursor = Cursors.Default;
    }
}

Screenshot