How to use DataGridView Control

Drag and drop DataGridView control from toolbox on WindowForm.

BindData in DataGridView

Code:

using System;
using System.Data;
using System.Data.SqlClient;
using System.Text;
using System.Windows.Forms;
  
namespace WindowsFormsApplication1
{
     public partial class  frmDataGridView : Form
    {
         public frmDataGridView()
         {
            InitializeComponent();
         }
  
         private void frmDataGridView_Load(object sender, EventArgs e)
         {
          //Connect to the database
      string constring =  "Server=(local);Database=my; User Id=sa; Password=sa";
            SqlConnection sqlcon = new SqlConnection(constring);
            //Open the connection
            sqlcon.Open();
            SqlCommand cmd = new SqlCommand();
            SqlDataAdapter da = new SqlDataAdapter();
            // Write the query
            cmd.CommandText = "select * from regform";
            da.SelectCommand = cmd;
            cmd.Connection = sqlcon;
            da.SelectCommand = cmd;
            //create a dataset
            DataSet ds =  new DataSet();
            da.Fill(ds);
            //Close the connection
            sqlcon.Close();
            dataGridView1.DataSource = ds.Tables[0];
         }
    }
}

Run the project

Data will show in DataGridView when application run.

Update data in DataGridView

Write code on Update Button.

Double click on Click event.

private void btnUpdate_Click(object sender, EventArgs e)
{
       SqlCommand cmd=new SqlCommand();  
            // write query  to update database
cmd.CommandText = "update regform set pass='"+dataGridView1.CurrentRow.Cells[1].Value+"',name='" + dataGridView1.CurrentRow.Cells[2].Value+  "' where id='" + dataGridView1.CurrentRow.Cells[0].Value + "'";
SqlConnection sqlcon = new SqlConnection(constring);
         cmd.Connection = sqlcon;
         // open the connection
         sqlcon.Open();
         cmd.ExecuteScalar();
 }

Click the cell in which you want to update then change value and click update button.