After creating the accessory objects of a database, you can get the application to perform the actual transactions. For a car rental company, we will create the object used to process the regular rental transactions. 

1. In the Microsoft SQL Server Management Studio, if necessary, expand the Databases, the bcr, and the Tables node.
   To create a new table, right the Tables node under bcr and click New Table...
2. Set the first column name to OrderProcessingID
3. Set its Data Type to int
4. In the lower section, expand Identity Specification and set the (Is Identify) field to Yes
5. On the Table Designer toolbar, click the Set Primary Key button
6. Complete the table with the following columns
    

   Column Name	Data Type	Allow Nulls
   OrderProcessingID	int
   OrderDate	varchar(50)
   OrderTime	varchar(50)
   EmployeeID	int	Uncheck
   CustomerID	int	Uncheck
   CarID	int	Uncheck
   CarCondition	varchar(20)
   TankLevel	varchar(50)
   StartDate	varchar(50)	Uncheck
   EndDate	varchar(50)
   NumberOfDays	varchar(50)
   RateApplied	varchar(50)
   SubTotal	varchar(50)
   TaxRate	varchar(50)
   TaxAmount	varchar(50)
   RentTotal	varchar(50)
   Notes	varchar(255)

7. Save the table as OrderProcessing
8. Right-click the table and click Relationships...
9. Click Add
10. Click Tables and Columns Specification and click its ellipsis button
11. Under Primary Key Table, select Employees and, under Employees, select EmployeeID
12. Under OrderProcessing, select EmployeeID
13. Click OK
14. Click Add again
15. Click the ellipsis button of Tables and Columns Specification
16. Under Primary Key Table, select Customers and, under Employees, select CustomerID
17. Under OrderProcessing, select CustomerID
18. Click OK
19. Click Add
20. Click the ellipsis button of Tables and Columns Specification
21. Under Primary Key Table, select Cars and, under Cars, select CarID
22. Click OK
23. Click Close
24. Close the table
25. When asked whether you want to save it, click Yes and Yes
26. To create a view, in the Object Explorer under bcr, right-click Views and click New View...
27. In the Add Table dialog box, click Employees
28. Click Add and click Close
29. In the Diagram pane (the top section), click the check box of EmployeeID
30. In the SQL pane, on the right side of SELECT EmployeeID, add
    LastName + ', ' + FirstName AS FullName
31. Save the view as EmployeesNames
     
    
32. Close it
33. In Microsoft Visual Studio, if necessary, open the bcr1 application created in the first section
    In the Data Source window, right-click dsBCR and click Configure DataSet With Wizard...
34. Expand the Tables node and click the check box of OrderProcessing
35. Expand the Views node and click the check box of EmployeesNames
     
    
36. Click Finish
37. To create a new form, on the main menu, click Project . Add Windows Form...
38. Set the name to OrderProcessing and click Add
39. Enlarge and heighten the form
40. In the Data Sources window, click OrderProcessing and click the arrow of its combo box
41. Select Details
42. From the Data Sources window, drag OrderProcessing and drop it on the form
43. While the controls are still selected, move them to the left side of the form (to create an empty space in the middle and on the right side of the form)
44. Again, from the Data Sources window, drag Employees and drop it on the form
45. While the DataGridView control is still selected on the form, press Delete to remove it from the form
46. Once again, from the Data Sources window, drag Customers and drop it in an empty area of the form
47. While the DataGridView control is still selected on the form, press Delete to remove it from the form
48. Once again, from the Data Sources window, drag Cars and drop it on the form
49. While the new controls are still selected on the form, press Delete to remove them from the form
50. Once again, from the Data Sources window, drag EmployeesNames and drop it on the form
51. While the DataGridView control is still selected on the form, press Delete to remove it
52. Delete the text boxes of OrderDate, OrderTime, EmployeeID, CustomerID, CarID, CarCondition, TankLevel, StartDate, and EndDate
53. Design the form as follows (you will add new controls to replace those that were deleted):
     

    Control Text Name Additional Properties Label Processed By:     ComboBox   cboEmployeeID   Label Order Processing ID:     TextBox       Label Order Date:     DateTimePicker   dtpOrderDate   Label Order Time:     DateTimePicker   dtpOrderTime Format: Time ShowUpDown: True GroupBox Customer     Label Select:     ComboBox cboCustomerID     Label Name:     TextBox   txtCustomerName   Label Address:     TextBox   txtCustomerAddress   TextBox   txtCustomerCity   TextBox   txtCustomerState   TextBox   txtCustomerZIPCode   TextBox   txtCustomerCountry   GroupBox Car     Label Select:     ComboBox cboCarID     Button Details btnCar Details   Label Make:     TextBox   txtCarMake   Label Model:     TextBox   txtCarModel   Label Year:     TextBox   txtCarYear   Label Mileage:     TextBox   txtCarMileage   Label Car Condition:     ComboBox   cboCarConditions Items: Excellent Good Driveable Needs Repair Label Tank Level:     ComboBox   cboTankLevels Items: Empty 1/4 Empty Half 3/4 Full Full Tank Label Start Date:     DateTimePicker   dtpStartRent   Label End Time:     DateTimePicker   dtpEndRent   Label Notes:     TextBox     Multiline: True ScrollBars: Vertical Label Rate Applied:     TextBox     Text: 0.00 TextAlign: Right Label Number Of Days:     TextBox     Text: 0 TextAlign: Right Label Sub Total:     TextBox     Text: 0.00 TextAlign: Right Label Tax Rate:     TextBox     Text: 5.75 TextAlign: Right Label %     Label Tax Amount:     TextBox     Text: 0.00 TextAlign: Right Label Rent Total:     TextBox     Text: 0.00 TextAlign: Right Button Close btnClose

54. Click each control that was added and change its data bindings
55. On the form, double-click the Details button in the Cars section and implement its Click event as follows:

    private void btnCarDetails_Click(object sender, EventArgs e)
    {
        if (cboCarID.Text == "")
            MessageBox.Show("No car is currently selected");
        else
        {
            CarDetails frmCarDetails = new CarDetails();
            string strCar =
                       string.Concat("SELECT * FROM Cars WHERE TagNumber = '",
                                    cboCarID.Text, "'");
            System.Data.SqlClient.SqlConnection conCar =
                       new System.Data.SqlClient.SqlConnection(
                   "Data Source=(local);Database=bcr;Integrated Security=yes");
                    System.Data.SqlClient.SqlCommand cmdCar =
                       new System.Data.SqlClient.SqlCommand(strCar, conCar);
                    conCar.Open();
    
            System.Data.SqlClient.SqlDataReader rdrCar = cmdCar.ExecuteReader();
    
            while (rdrCar.Read())
            {
                frmCarDetails.txtTagNumber.Text = rdrCar.GetString(1);
                frmCarDetails.txtMake.Text = rdrCar.GetString(2);
                frmCarDetails.txtModel.Text = rdrCar.GetString(3);
                frmCarDetails.txtYear.Text = rdrCar.GetInt32(4).ToString();
                frmCarDetails.txtMileage.Text = rdrCar.GetInt32(5).ToString();
                frmCarDetails.cboCategory.Text = rdrCar.GetString(6);
                frmCarDetails.txtPictureName.Text = rdrCar.GetString(7);
                frmCarDetails.chkK7Player.Checked = rdrCar.GetBoolean(8);
                frmCarDetails.chkDVDPlayer.Checked = rdrCar.GetBoolean(9);
                frmCarDetails.chkCDPlayer.Checked = rdrCar.GetBoolean(10);
                frmCarDetails.chkAvailable.Checked = rdrCar.GetBoolean(11);
                frmCarDetails.pctCar.Image =
                	Image.FromFile(frmCarDetails.txtPictureName.Text);
            }
    
            frmCarDetails.btnPicture.Visible = false;
            frmCarDetails.btnSubmit.Visible = false;
            frmCarDetails.ShowDialog();
            conCar.Close();
        }
    }

56. Return to the OrderProcessing form, click the text box on the right side of Number Of Days
57. In the Properties window, click the Events box and generate the event of the Leave field
58. Define it as follows:

    private void numberOfDaysTextBox_Leave(object sender, EventArgs e)
    {
        int numberOfDays = 0;
        decimal rateApplied = 0.00M, subTotal = 0.00M;
    
        try {
    	 rateApplied = decimal.Parse(rateAppliedTextBox.Text);
        }
        catch(FormatException )
        {
    	 MessageBox.Show("Invalid value for the rate applied");
        }
    
        try {
    	 numberOfDays = int.Parse(numberOfDaysTextBox.Text);
        }
        catch(FormatException )
        {
    	 MessageBox.Show("Invalid value for the number of days");
        }
    
        subTotal = rateApplied * numberOfDays;
        subTotalTextBox.Text = subTotal.ToString("F");
    }

59. Return to OrderProcessing the form, click the text box on the right side of Tax Rate
60. In the Events section of the Properties window, generate the event of the Leave field
61. Define it as follows:

    private void taxRateTextBox_Leave(object sender, EventArgs e)
    {
        decimal subTotal = 0.00M, taxRate = 0.00M,
                taxAmount = 0.00M, rentTotal = 0.00M;
    			 
        try {
            subTotal = decimal.Parse(subTotalTextBox.Text);
        }
        catch(FormatException )
        {
    	 MessageBox.Show("Invalid value for sub-tota");
        }
    
        try {
            taxRate = decimal.Parse(taxRateTextBox.Text);
        }
        catch(FormatException )
        {
    	 MessageBox.Show("Invalid value for the tax rate");
        }
    
        taxAmount = subTotal * taxRate / 100;
        rentTotal = subTotal + taxAmount;
    
        taxAmountTextBox.Text = taxAmount.ToString("F");
        rentTotalTextBox.Text = rentTotal.ToString("F");
    }

62. Return to OrderProcessing the form and double-click the Close button
63. Implement its even as follows:

    private void btnClose_Click(object  sender, EventArgs  e)
    {
    	 Close();
    }

64. Access the Central form
65. Add a button to it and set its properties as follows:
    Text: OrderProcessing
    (Name): btnOrderProcessing
66. Double-click the Customers button
67. In the top section of the file, under the #pragma once line, type
    #include "OrderProcessing.h"
68. Scroll to the bottom of the file and implement the even as follows:

    private void btnOrderProcessing_Click(object sender, EventArgs e)
    {
        OrderProcessing frmOrder = new OrderProcessing();
        frmOrder.ShowDialog();
    }

69. Execute the application to test it
70. Display the OrderProcessing form
71. To process an order, click the + button and complete the form
     
    
72. After completing the form, click the Save button
73. Close the form(s)