public void display()
        {
            SqlConnection  con   = Database_Connection.OpenCon();
            string         query = "select * from operator_info";
            SqlCommand     cmd   = new SqlCommand(query, con);
            DataTable      dt    = new DataTable();
            SqlDataAdapter da    = new SqlDataAdapter(cmd);

            da.Fill(dt);
            dataGridView1.DataSource = dt;
            cmd.ExecuteNonQuery();
            Database_Connection.CloseCon();
        }
        private void buttonsearch_Click(object sender, EventArgs e)
        {
            SqlConnection  con   = Database_Connection.OpenCon();
            string         query = "select * from operator_info where id='" + bunifuMaterialTextboxid.Text + "'";
            SqlCommand     cmd   = new SqlCommand(query, con);
            DataTable      dt    = new DataTable();
            SqlDataAdapter da    = new SqlDataAdapter(cmd);

            da.Fill(dt);
            dataGridView1.DataSource = dt;
            cmd.ExecuteNonQuery();
            Database_Connection.CloseCon();
        }
        private void Buttondelete_Click(object sender, EventArgs e)
        {
            SqlConnection con   = Database_Connection.OpenCon();
            string        query = "delete from operator_info where id='" + bunifuMaterialTextboxid.Text + "'";
            SqlCommand    cmd   = new SqlCommand(query, con);

            cmd.Parameters.Add("@id", bunifuMaterialTextboxid.Text);
            cmd.Parameters.Add("@name", bunifuMaterialTextboxname.Text);
            cmd.Parameters.Add("@fare", bunifuMaterialTextboxfare.Text);

            cmd.ExecuteNonQuery();
            MessageBox.Show("delete successfully");
            display();
            Database_Connection.CloseCon();
        }
        private void Buttoninsert_Click(object sender, EventArgs e)
        {
            SqlConnection con   = Database_Connection.OpenCon();
            string        query = "insert into operator_info(id,name,fare) values (@id,@name,@fare)";
            SqlCommand    cmd   = new SqlCommand(query, con);

            cmd.Parameters.Add("@id", bunifuMaterialTextboxid.Text);
            cmd.Parameters.Add("@name", bunifuMaterialTextboxname.Text);
            cmd.Parameters.Add("@fare", bunifuMaterialTextboxfare.Text);

            cmd.ExecuteNonQuery();
            MessageBox.Show("insert successfully");
            display();
            Database_Connection.CloseCon();
        }