Operations on Gridview

Please tell me the "GENERAL CODING" for all the operations( insertion, deletion, edition(updation, cancel), selection, paging, sorting) that can be performed on gridview (programmitically not by declarative).

what i have tried is as below"

protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
       string id = GridView1.DataKeys[e.RowIndex]["id"].ToString();
        TextBox tx1 = (TextBox)GridView1.Rows[e.RowIndex].Cells[2].Controls[1];
        TextBox tx2 = (TextBox)GridView1.Rows[e.RowIndex].Cells[3].Controls[1];
        CheckBox cb = (CheckBox)GridView1.Rows[e.RowIndex].Cells[4].Controls[1];
        string qu = "update emp set Name='" + tx1.Text + "',City='" + tx2.Text + "',IsTemp ='"+ cb.Checked +"' where id=" + id + "";
        int i = obj.ExecuteQuery(qu);
        GridView1.EditIndex = -1;
        if (i > 0)
        {
            Bind();
        }
    }

Supppose i have written the code for rest operations in the similar manner, so as i have used Cells[2].Controls[1];  whenver i add or delete any column, i have to rewrite the code, therefore i need the "GENERAL CODING" for all the operations( insertion, deletion, edition(updation, cancel), selection, paging, sorting) that can be performed on gridview.