private void buttonAddR_Click(object sender, EventArgs e) { string keyWord = textBoxname.Text; SqlConnection conn = new SqlConnection(myconnstr); SqlDataAdapter sda = new SqlDataAdapter("Select * from tbl_room where roomName LIKE '%" + keyWord + "%'", conn); DataTable DTs = new DataTable(); sda.Fill(DTs); Regex regex = new Regex(@"^[0-9]+$"); if (comboBoxBuildingName.Text == "") { MessageBox.Show("Please Select Building name !"); } else if (comboBoxFloorNo.Text == "") { MessageBox.Show("Please Select Floor No !"); } else if (textBoxname.Text == "") { MessageBox.Show("Room name is required !"); } else if (DTs.Rows.Count != 0) { MessageBox.Show("Room name is already used, Please use another name !"); } else if (textBoxcapacity.Text == "") { MessageBox.Show("Capacity are required !"); } else if (!regex.IsMatch(textBoxcapacity.Text)) { MessageBox.Show("Capacity fields must only numeric value!"); } else if (comboBoxType.Text == "") { MessageBox.Show("Room Type is required !"); } else { r.BuildingName = comboBoxBuildingName.Text; r.RoomName = textBoxname.Text; r.FloorNo = int.Parse(comboBoxFloorNo.Text); r.Capacity = int.Parse(textBoxcapacity.Text); r.Types = comboBoxType.Text; //Insert data into data base using Insert method bool success = r.Insert(r); if (success == true) { MessageBox.Show("New Room Successfully Added"); clear(); } else { MessageBox.Show("Failed to add Room, Try again!!"); } //Load data on datagrid DataTable dt = r.Select(); dataGridViewRoom.DataSource = dt; } }