how to update records from dataGridView to database ?

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C#

WinForms

DataGrid

I searched on google but I couldn't get the right answer for my project..
I create a form in which i want to Insert,update and delete the records through the dataGridView..

My code is:-

public partial class orderListDetails : Form
    {
        Data_Conn DC;
        string DelValue = string.Empty;
        public orderListDetails()
        {
            InitializeComponent();
            DC = new Data_Conn(Application.StartupPath);                       
        }

        private void orderListDetails_Load(object sender, EventArgs e)
        {
            DC.SelectSta("select proName as Name,proComp as Company,proQty as Qty,proUnit as Unit from orderList", "orderList");
            dataGridView1.DataSource = DC.dataSet;
            dataGridView1.DataMember = "orderList";
            
        }

        private void button5_Click(object sender, EventArgs e)
        {
            this.Dispose();
        }

        private void btnAddNew_Click(object sender, EventArgs e)
        {

           
            DC.CmdStatement("insert into orderList values('" + textBox1.Text + "','" + comboBox1.Text + "'," + Convert.ToInt32(textBox2.Text) + ",'" + comboBox2.Text + "')");
            
            DC.SelectSta("select proName as Name,proComp as Company,proQty as Qty,proUnit as Unit from orderList", "orderList");
            dataGridView1.DataSource = DC.dataSet;
            dataGridView1.DataMember = "orderList";
            dataGridView1.Refresh();    
        }

        private void btnDelete_Click(object sender, EventArgs e)
        {
            try
            {
                
                DialogResult dr = MessageBox.Show("Do You want to delete the product details?", "Confirmation", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
                if (dr == DialogResult.Yes)
                {
                    dataGridView1.Rows.RemoveAt(dataGridView1.CurrentRow.Index);
                    DC.CmdStatement("delete from orderList where proName='"+DelValue+"'");                    
                    DC.SelectSta("select proName as Name,proComp as Company,proQty as Qty,proUnit as Unit from orderList", "orderList");
                    dataGridView1.DataSource = DC.dataSet;
                    dataGridView1.DataMember = "orderList";                   
                }
            }
            catch
            { }
        }
        private void btnUpdate_Click(object sender, EventArgs e)
        {
            DC.adpt.Update(DC.dataSet, "orderList");
        }

        private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
        {                                                            
            DelValue = dataGridView1[0, e.RowIndex].Value.ToString();                          
        }
    }

when i click on Update button Its shows the error message

Update requires a valid UpdateCommand when passed DataRow collection with modified rows.

How to Update that record in database??

thanks in Advance....