Microsoft Visual C#: Introduction to Data Adapters and Data Sets

After a data set has been filled, the records are available. Through the features of a data set, you can access the table(s), its(their) column(s), and its(their) record(s). You can either create a new record, check the existence of a record, delete an existing record, or edit/update a record.

1. Create a new Windows Application named GeorgetownDryCleaner5
2. To create a new form, on the main menu, click Project -> Add Windows Form...
3. Set the Name to Employees and press Enter
4. Design the form as follows:
    

   Control Name Text Additional Properties Group Box   New Employee   Label   First Name:   TextBox txtFirstName     Label   Last Name:   TextBox txtLastName     Label   Employee #:   MaskedTextBox txtEmployeeNumber   Mask: 00-000 Label   Title:   TextBox txtTitle     Label   Hourly Salary:   TextBox txtHourlySalary   TextAlign: Right Button btnSubmit Submit   DataGridView dgvEmployees     Button btnClose Close

5. Save the form
6. To create a new form, on the main menu, click Project -> Add Windows Form...
7. Set the Name to Customers and press Enter
8. Design the form as follows:
    

   Control Name Text Additional Properties Group Box   New Customer   Label   Customer Phone:   MaskedTextBox txtCustomerPhone   Mask: (999) 000-0000 Label   Customer Name:   TextBox txtCustomerName     Button btnSubmit Submit   DataGridView dgvCustomers     Button btnClose Close

9. Save the form
10. In the Solution Explorer, right-click Form1.cs and click Rename
11. Type OrderCleaning.cs and press Enter twice
12. Design the form as follows:
     

    Control Name Text Additional Properties GroupBox   Processed By   Label   Employee #:   MaskedTextBox txtEmployeeNumber   Mask: 00-000 Button    btnNewEmployee  New Employee...   Label   Employee Name:   TextBox txtEmployeeName     GroupBox   Processed For   Label   Customer Phone:   MaskedTextBox txtCustomerPhone   Mask: (999) 000-0000 Button  btnNewCustomer  New Cust...   Label   Customer Name:   TextBox txtCustomerName     GroupBox   Order Timing   Label   Date Left:   DateTimePicker dtpDateLeft     Label   Time Left:   DateTimePicker dtpTimeLeft   Format: Time Label   Date Expected:   DateTimePicker dtpDateExpected     Label   Time Expected:   DateTimePicker dtpTimeExpected   Format: Time Label   D&ate Picked Up:   DateTimePicker dtpDatePickedUp     Label   Time Pic&kep Up:   DateTimePicker dtpTimePickedUp     GroupBox   Order Processing   Label   Item Type   Label   Unit Price   Label   Qty   Label   Sub Total   Label   Shirts   TextBox txtUnitPriceShirts 1.25 TextAlign: Right TextBox txtQuantityShirts 0 TextAlign: Right TextBox txtSubTotalShirts 0.00 TextAlign: Right Label   Pants   TextBox txtUnitPricePants 1.95 TextAlign: Right TextBox txtQuantityPants   TextAlign: Right TextBox txtSubTotalPants 0.00 TextAlign: Right ComboBox cbxItem1Name None Items: None Women Suit Dress Regular Skirt Skirt With Hook Men's Suit 2Pc Men's Suit 3Pc Sweaters Silk Shirt Tie Coat Jacket Swede TextBox txtUnitPriceItem1 0.00 TextAlign: Right TextBox txtQuantityItem1 0 TextAlign: Right TextBox txtSubTotalItem1 0.00 TextAlign: Right ComboBox cbxItem2Name None Items: None Women Suit Dress Regular Skirt Skirt With Hook Men's Suit 2Pc Men's Suit 3Pc Sweaters Silk Shirt Tie Coat Jacket Swede TextBox txtUnitPriceItem2 0.00 TextAlign: Right TextBox txtQuantityItem2 0 TextAlign: Right TextBox txtSubTotalItem2 0.00 TextAlign: Right ComboBox cbxItem3Name None Items: None Women Suit Dress Regular Skirt Skirt With Hook Men's Suit 2Pc Men's Suit 3Pc Sweaters Silk Shirt Tie Coat Jacket Swede TextBox txtUnitPriceItem3 0.00 TextAlign: Right TextBox txtQuantityItem3 0 TextAlign: Right TextBox txtSubTotalItem3 0.00 TextAlign: Right ComboBox cbxItem4Name None Items: None Women Suit Dress Regular Skirt Skirt With Hook Men's Suit 2Pc Men's Suit 3Pc Sweaters Silk Shirt Tie Coat Jacket Swede TextBox txtUnitPriceItem4 0.00 TextAlign: Right TextBox txtQuantityItem4 0 TextAlign: Right TextBox txtSubTotalItem4 0.00 TextAlign: Right GroupBox   Order Summary   Label   Cleaning Total:   TextBox txtCleaningTotal 0.00 TextAlign: Right Label   Tax Rate:   TextBox txtTaxRate 7.75 TextAlign: Right Label   %   Label   Tax Amount:   TextBox txtTaxAmount 0.00 TextAlign: Right Label   Net Total:   TextBox txtNetPrice 0.00 TextAlign: Right Label   Order &Status:   ComboBox cbxOrderStatus     Button btnSave Save   GroupBox    Cleaning Order Details    Label   &Receipt #:   TextBox txtCleaningOrderID     Button btnOpen Open   Label    Notes   TextBox  txtNotes     Button btnNewCleaningOrder New Cleaning Order   Button btnClose Close

13. Double-click the New Employee button and implement its event as follows:
    

    private void btnNewEmployee_Click(object sender, EventArgs e)
    {
        Employees clerks = new Employees();
        clerks.ShowDialog();
    } 

14. Return to the form and double-click the New Cust button
15. Implement the event as follows:
    

    private void btnNewCustomer_Click(object sender, EventArgs e)
    {
        Customers clients = new Customers();
        clients.ShowDialog();
    } 

16. Return to the form and double-click an unoccupied area of its body
17. To create a database, including the tables with their primary keys and their foreign keys, implement the Load event as follows:
    

    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;
    using System.Data.SqlClient;
    
    namespace GeorgetownDryCleaner5
    {
        public partial class OrderCleaning: Form
        {
    	public Exercise()
    	{
    	    InitializeComponent();
            }
    
    	private void OrderCleaning_Load(object sender, EventArgs e)
    	{
    	    using (SqlConnection conGCS = 
    	        new SqlConnection("Data Source=(local); " +
    			 	  "Integrated Security='SSPI';"))
       	    {
    	    	string strCreateDatabase = 
    		    "CREATE DATABASE GeorgetownDryCleaner1";
    
    		SqlCommand cmdGCS = new SqlCommand(strCreateDatabase,
    						   conGCS);
    
    		conGCS.Open();
    	    	cmdGCS.ExecuteNonQuery();
    
    	        MessageBox.Show("A database named " + 
    		    "GeorgetownDryCleaner1 has been created");
    	   }
    
    	   using (SqlConnection conGCS =
    	   	new SqlConnection("Data Source=(local); " +
    			"Database='GeorgetownDryCleaner1'; " +
    				  "Integrated Security='SSPI';"))
    	    {
    	        string strCreateTable = "CREATE TABLE Employees( " +
    			"EmployeeID int identity(1, 1) NOT NULL, " +
    			"EmployeeNumber nchar(6), " +
    			"FirstName varchar(32), " +
    			"LastName varchar(32) NOT NULL, " +
    			"FullName AS (([LastName]+', ')+[FirstName]), " +
    			"Title varchar(80), " +
    			"HourlySalary smallmoney, " +
    			"CONSTRAINT PK_Employees PRIMARY KEY (EmployeeID));";
    
    	        SqlCommand cmdGCS = new SqlCommand(strCreateTable, conGCS);
    
        		conGCS.Open();
    	    	cmdGCS.ExecuteNonQuery();
    	    	MessageBox.Show("A table named Employees has been created");
    	    }
    
    	    using (SqlConnection conGCS =
    	    	new SqlConnection("Data Source=(local); " +
    			          "Database='GeorgetownDryCleaner1'; " +
    			          "Integrated Security='SSPI';"))
    	    {
    	    	string strCreateTable = "CREATE TABLE Customers( " +
    			"CustomerID int identity(1, 1) NOT NULL, " +
    			"PhoneNumber varchar(20), " +
    			"FullName varchar(80), " +
    			"CONSTRAINT PK_Customer PRIMARY KEY (CustomerID));";
    
    	    	SqlCommand cmdGCS = new SqlCommand(strCreateTable, conGCS);
    
    	    	conGCS.Open();
    	    	cmdGCS.ExecuteNonQuery();
    	    	MessageBox.Show("A table named Customers has been created");
    	    }
    
    	    using (SqlConnection conGCS =
    	    	new SqlConnection("Data Source=(local); " +
    			          "Database='GeorgetownDryCleaner1'; " +
    			          "Integrated Security='SSPI';"))
    	    {
    	    	string strCreateTable = "CREATE TABLE CleaningOrders( " +
    			"CleaningOrderID int identity(1000, 1) NOT NULL, " +
    			"EmployeeNumber nchar(6) NOT NULL, " +
    			"CustomerNumber varchar(20) NOT NULL, " +
    			"DateLeft smalldatetime, " +
    			"TimeLeft smalldatetime, " +
    			"DateExpected smalldatetime, " +
    			"TimeExpected smalldatetime, " +
    			"OrderStatus varchar(50), " +
    			"DatePickedUp smalldatetime, " +
    			"TimePickedUp smalldatetime, " +
    			"UnitPriceShirts smallmoney, " +
    			"QuantityShirts smallmoney, " +
    			"SubTotalShirts smallmoney, " +
    			"UnitPricePants smallmoney, " +
    			"QuantityPants smallmoney, " +
    			"SubTotalPants smallmoney, " +
    			"Item1Name varchar(50), " +
    			"UnitPriceItem1 smallmoney, " +
    			"QuantityItem1 smallmoney, " +
    			"SubTotalItem1 smallmoney, " +
    			"Item2Name varchar(50), " +
    			"UnitPriceItem2 smallmoney, " +
    			"QuantityItem2 smallmoney, " +
    			"SubTotalItem2 smallmoney, " +
    			"Item3Name varchar(50), " +
    			"UnitPriceItem3 smallmoney, " +
    			"QuantityItem3 smallmoney, " +
    			"SubTotalItem3 smallmoney, " +
    			"Item4Name varchar(50), " +
    			"UnitPriceItem4 smallmoney, " +
    			"QuantityItem4 smallmoney, " +
    			"SubTotalItem4 smallmoney, " +
    			"CleaningTotal smallmoney, " +
    			"TaxRate decimal(6,2), " +
    			"TaxAmount smallmoney, " +
    			"NetPrice smallmoney, " +
    			"Text smallmoney);";
    
    	        SqlCommand cmdGCS = new SqlCommand(strCreateTable, conGCS);
    
    	    	conGCS.Open();
    	    	cmdGCS.ExecuteNonQuery();
    	    	MessageBox.Show("A table named CleaningOrders has been created");
    	    }
        	}
        }
    }

18. Execute the application to create the database and its tables
19. Close the form and return to your programming environment
20. In the source file, delete the whole content of the Load event and return to the form
21. Access the Employees form
22. Double-click an unoccupied area of the form to generate its Load event and implement it as follows:
    

    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;
    using System.Data.SqlClient;
    
    namespace GeorgetownDryCleaner5
    {
        public partial class Employees : Form
        {
    	public Employees()
    	{
    	    InitializeComponent();
    	}
    
    	void ShowEmployees()
    	{
    	    using (SqlConnection Connect =
    		new SqlConnection("Data Source=(local);" +
    			"Database='GeorgetownDryCleaner1';" +
    			"Integrated Security=SSPI;"))
    	    {
    		string strEmployees =
    			"SELECT * FROM Employees;";
    		SqlCommand cmdEmployees =
    		    new SqlCommand(strEmployees, Connect);
    		SqlDataAdapter daEmployees = new SqlDataAdapter();
    
    		daEmployees.SelectCommand = cmdEmployees;
    		DataSet dsEmployees = new DataSet("EmployeesSet");
    		daEmployees.Fill(dsEmployees);
    
    		Connect.Open();
    
    	    	dgvEmployees.DataSource = dsEmployees;
    		dgvEmployees.DataMember = dsEmployees.Tables[0].TableName;
    	   }
    	}
    
    	private void Employees_Load(object sender, EventArgs e)
    	{
    	    ShowEmployees();
    	}
        }
    }

23. Return to the form and double-click the Submit button
24. Implement its event as follows:
    

    private void btnSubmit_Click(object sender, EventArgs e)
    {
        using (SqlConnection Connect =
    	new SqlConnection("Data Source=(local);" +
    		"Database='GeorgetownDryCleaner1';" +
    		"Integrated Security=SSPI;"))
        {
    	string strEmployees = "INSERT INTO Employees(EmployeeNumber, " +
    			      "FirstName, LastName, Title, HourlySalary) " +
    			      "VALUES('" + txtEmployeeNumber.Text +
    			      "', '" + txtFirstName.Text + "', '" +
    			      txtLastName.Text + "', '" + txtTitle.Text +
    			      "', '" + txtHourlySalary.Text + "');";
    	SqlCommand cmdEmployees = new SqlCommand(strEmployees,
    						 Connect);
    
    	Connect.Open();
    	cmdEmployees.ExecuteNonQuery();
    
    	txtEmployeeNumber.Text = "";
    	txtFirstName.Text = "";
    	txtLastName.Text = "";
    	txtTitle.Text = "";
    	txtHourlySalary.Text = "0.00";
    
    	ShowEmployees();
        }
    }

25. Return to the form and double-click the Close button
26. Implement its event as follows:
    

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

27. Access the Customers form
28. Double-click an unoccupied area of the form to generate its Load event and implement it as follows:
    

    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;
    using System.Data.SqlClient;
    
    namespace GeorgetownDryCleaner5a
    {
        public partial class Customers : Form
        {
    	public Customers()
    	{
    	    InitializeComponent();
    	}
    
    	void ShowCustomers()
    	{
    	    using (SqlConnection cnnCustomers =
    		new SqlConnection("Data Source=(local);" +
    			"Database='GeorgetownDryCleaner1';" +
    			"Integrated Security=SSPI;"))
    	    {
    		string strCustomers = "SELECT * FROM Customers;";
    		SqlCommand cmdCustomers =
    		    new SqlCommand(strCustomers, cnnCustomers);
    		SqlDataAdapter daCustomers = new SqlDataAdapter();
    
    		daCustomers.SelectCommand = cmdCustomers;
    		DataSet dsCustomers = new DataSet("CustomersSet");
    		daCustomers.Fill(dsCustomers);
    
    		cnnCustomers.Open();
    
    		dgvCustomers.DataSource = dsCustomers;
    		dgvCustomers.DataMember = dsCustomers.Tables[0].TableName;
        	    }
    	}
    
    	private void Customers_Load(object sender, EventArgs e)
    	{
    	    ShowCustomers();
    	}
        }
    } 

29. Return to the form and double-click the Submit button
30. Implement its event as follows:
    

    private void btnSubmit_Click(object sender, EventArgs e)
    {
        using (SqlConnection cnnCustomers =
    	new SqlConnection("Data Source=(local);" +
    			  "Database='GeorgetownDryCleaner1';" +
    			  "Integrated Security=SSPI;"))
        {
    	string strCustomers = "INSERT INTO Customers(PhoneNumber, " +
    			      "FullName) " +
    			      "VALUES('" + txtCustomerPhone.Text +
    			      "', '" + txtCustomerName.Text + "');";
    	SqlCommand cmdCustomers = new SqlCommand(strCustomers,
    						 cnnCustomers);
    
    	cnnCustomers.Open();
    	cmdCustomers.ExecuteNonQuery();
    
    	txtCustomerPhone.Text = "";
    	txtCustomerName.Text = "";
    
    	ShowCustomers();
        }
    } 

31. Return to the form and double-click the Close button
32. Implement its event as follows:
    

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

33. Access the CleaningOrders form
34. On the form, click the txtEmployeeNumber text box and, on the Properties window, click the Events button
35. In the Events section, double-click Leave and implement its event as follows:
    

    private void txtEmployeeNumber_Leave(object sender, EventArgs e)
    {
        using (SqlConnection Connect =
    	new SqlConnection("Data Source=(local);" +
    			  "Database='GeorgetownDryCleaner1';" +
    			  "Integrated Security=SSPI;"))
        {
    	string strEmployees =
    	    "SELECT FullName FROM Employees WHERE EmployeeNumber = '" +
    		txtEmployeeNumber.Text + "';";
    	SqlCommand cmdEmployees =
    		new SqlCommand(strEmployees, Connect);
    	SqlDataAdapter daEmployees = new SqlDataAdapter();
    
    	daEmployees.SelectCommand = cmdEmployees;
    	DataSet dsEmployees = new DataSet("EmployeesSet");
    	daEmployees.Fill(dsEmployees);
    
    	Connect.Open();
    
    	foreach (DataRow rowEmployee in dsEmployees.Tables[0].Rows)
    	{
    	    foreach (DataColumn colEmployee in dsEmployees.Tables[0].Columns)
    	    {
    		txtEmployeeName.Text = rowEmployee[colEmployee].ToString();
    	    }
    	    break;
    	}
        }
    }

36. Return to the CleaningOrders form
37. On the form, click the txtCustomerPhone text box and, in the Events section of the Properties window, double-click Leave
38. Implement its event as follows:
    

    private void txtCustomerPhone_Leave(object sender, EventArgs e)
    {
        using (SqlConnection cnnCustomers =
    	new SqlConnection("Data Source=(local);" +
    			  "Database='GeorgetownDryCleaner1';" +
    			  "Integrated Security=SSPI;"))
        {
    	string strCustomers =
    		"SELECT FullName FROM Customers WHERE PhoneNumber = '" +
    		txtCustomerPhone.Text + "';";
    	SqlCommand cmdCustomers =
    	new SqlCommand(strCustomers, cnnCustomers);
    	SqlDataAdapter daCustomers = new SqlDataAdapter();
    
    	daCustomers.SelectCommand = cmdCustomers;
    	DataSet dsCustomers = new DataSet("CustomersSet");
    	daCustomers.Fill(dsCustomers);
    
    	cnnCustomers.Open();
    
    	foreach (DataRow rowCustomer in dsCustomers.Tables[0].Rows)
    	{
    	    foreach (DataColumn colCustomer in dsCustomers.Tables[0].Columns)
    	    {
    		txtCustomerName.Text = rowCustomer[colCustomer].ToString();
    	    }
    	    break;
    	}
        }
    }

39. Return to the CleaningOrders form
40. On the form, double-click the New Cleaning Order button and implement its event as follows:
    

    private void btnNewCleaningOrder_Click(object sender, EventArgs e)
    {
        txtEmployeeNumber.Text = "";
        txtEmployeeName.Text = "";
        txtCustomerPhone.Text = "";
        txtCustomerName.Text = "";
    
        txtCleaningOrderID.Text = "";
    
        dtpDateLeft.Value = DateTime.Today;
        dtpTimeLeft.Value = DateTime.Today;
        dtpDateExpected.Value = DateTime.Today;
        dtpTimeExpected.Value = DateTime.Today;
    
        cbxOrderStatus.Text = "Not Yet Ready";
        dtpDatePickedUp.Value = DateTime.Today;
        dtpTimePickedUp.Value = DateTime.Today;
    
        txtUnitPriceShirts.Text = "1.25";
        txtQuantityShirts.Text = "0";
        txtSubTotalShirts.Text = "0.00";
    
        txtUnitPricePants.Text = "1.95";
        txtQuantityPants.Text = "0";
        txtSubTotalPants.Text = "0.00";
        cbxItem1Name.Text = "None";
        txtUnitPriceItem1.Text = "0.00";
        txtQuantityItem1.Text = "0";
        txtSubTotalItem1.Text = "0.00";
        cbxNameItem2.Text = "None";
        txtUnitPriceItem2.Text = "0.00";
        txtQuantityItem2.Text = "0";
        txtSubTotalItem2.Text = "0.00";
        cbxNameItem3.Text = "None";
        txtUnitPriceItem3.Text = "0.00";
        txtQuantityItem3.Text = "0";
        txtSubTotalItem3.Text = "0.00";
        cbxNameItem4.Text = "None";
        txtUnitPriceItem4.Text = "0.00";
        txtQuantityItem4.Text = "0";
        txtSubTotalItem4.Text = "0.00";
    
        txtCleaningTotal.Text = "0.00";
        txtTaxRate.Text = "7.75";
        txtTaxAmount.Text = "0.00";
        txtCleaningTotal.Text = "0.00";
        txtNotes.Text = "";
    
        txtEmployeeNumber.Focus();
    }

41. Change to Load event as follows:
    

    private void OrderCleaning_Load(object sender, EventArgs e)
    {
        btnNewCleaningOrder_Click(sender, e);
    }

42. Double-click the Time Left control and implement its ValueChanged event as follows:
    

    private void dtpTimeLeft_ValueChanged(object sender, EventArgs e)
    {
        DateTime dateLeft = this.dtpDateLeft.Value;
        DateTime timeLeft = this.dtpTimeLeft.Value;
    
        DateTime time9AM = new DateTime(timeLeft.Year, timeLeft.Month,
                                        timeLeft.Day, 9, 0, 0);
    
        // If the customer leaves clothes before 9AM...
        if (timeLeft <= time9AM)
        {
            // ... then they should be ready the same day after 5PM
            this.dtpDateExpected.Value = dateLeft;
            this.dtpTimeExpected.Value = new DateTime(dateLeft.Year,
                                                      dateLeft.Month,
    					dateLeft.Day, 17, 0, 0);
        }
        else
        {
            // If the clothes were left after 9AM,
            // then they will be available
    	// the following business morning at 8AM
            // If the following day is Sunday,
            // then they will be ready the following Monday
            if (dateLeft.DayOfWeek == DayOfWeek.Saturday)
            {
                dtpDateExpected.Value = dateLeft.AddDays(2.00D);
                dtpTimeExpected.Value = new DateTime(dateLeft.Year,
                                                     dateLeft.Month,
    					dateLeft.Day + 2, 8, 0, 0);
            }
            else
            {
                dtpDateExpected.Value = new DateTime(dateLeft.Year,
                                                     dateLeft.Month,
    						 dateLeft.Day + 1);
                dtpTimeExpected.Value = new DateTime(dateLeft.Year,
                                                     dateLeft.Month,
    					dateLeft.Day + 1, 8, 0, 0);
            }
        }
    }

43. Return to the form and double-click the Save button
44. Implement its event as follows:
    

    private void btnSave_Click(object sender, EventArgs e)
    {
        string strCommand = "";
    	using (SqlConnection cnnCleaningOrders =
    	    new SqlConnection("Data Source=(local);" +
    		"Database='GeorgetownDryCleaner1';" +
    		"Integrated Security=SSPI;"))
        {
    	// If the Receipt Number is empty, it appears that
    	// the user/clerk wants to create a new cleaning order
    	if (txtCleaningOrderID.Text.Length == 0)
    	{
    	    strCommand = "INSERT INTO CleaningOrders( " +
    			 "EmployeeNumber, CustomerNumber, DateLeft, " +
    			 "TimeLeft, DateExpected, TimeExpected, " +
    			 "OrderStatus, DatePickedUp, " +
    			 "TimePickedUp, UnitPriceShirts, " +
    			 "QuantityShirts, SubTotalShirts, " +
    			 "UnitPricePants, QuantityPants, " +
    			 "SubTotalPants, Item1Name, " +
    			 "UnitPriceItem1, QuantityItem1, " +
    			 "SubTotalItem1, Item2Name, " +
    			 "UnitPriceItem2, QuantityItem2, " +
    			 "SubTotalItem2, Item3Name, " +
    			 "UnitPriceItem3, QuantityItem3, " +
    			 "SubTotalItem3, Item4Name, " +
    			 "UnitPriceItem4, QuantityItem4, " +
    			 "SubTotalItem4, CleaningTotal, " +
    			 "TaxRate, TaxAmount, NetPrice, Notes) " +
    			 "VALUES('" + txtEmployeeNumber.Text + "', '" +
    			 txtCustomerPhone.Text + "', '" +
    			 dtpDateLeft.Value.ToString("d") + "', '" +
    			 dtpTimeLeft.Value.ToString("t") + "', '" +
    			 dtpDateExpected.Value.ToString("d") + "', '" +
    			 dtpTimeExpected.Value.ToString("t") + "', '" +
    			 cbxOrderStatus.Text + "', '" +
    			 dtpDatePickedUp.Value.ToString("d") + "', '" +
    			 dtpDatePickedUp.Value.ToString("t") + "', '" +
    			 txtUnitPriceShirts.Text + "', '" + 
    			 txtQuantityShirts.Text + "', '" + 
    			 txtSubTotalShirts.Text + "', '" +
    			 txtUnitPricePants.Text + "', '" + 
    			 txtQuantityPants.Text + "', '" +
    			 txtSubTotalPants.Text + "', '" + 
    			 cbxItem1Name.Text + "', '" +
    			 txtUnitPriceItem1.Text + "', '" + 
    			 txtQuantityItem1.Text + "', '" +
    			 txtSubTotalItem1.Text + "', '" + 
    			 cbxItem2Name.Text + "', '" +
    			 txtUnitPriceItem2.Text + "', '" + 
    			 txtQuantityItem2.Text + "', '" +
    			 txtSubTotalItem2.Text + "', '" + 
    			 cbxItem3Name.Text + "', '" +
    			 txtUnitPriceItem3.Text + "', '" + 
    			 txtQuantityItem3.Text + "', '" +
    			 txtSubTotalItem3.Text + "', '" + 
    			 cbxItem4Name.Text + "', '" +
    			 txtUnitPriceItem4.Text + "', '" + 
    			 txtQuantityItem4.Text + "', '" +
    			 txtSubTotalItem4.Text + "', '" + 
    			 txtCleaningTotal.Text + "', '" +
    			 txtTaxRate.Text + "', '" + 
    			 txtTaxAmount.Text + "', '" +
    			 txtNetPrice.Text + "', '" + txtNotes.Text + "');";
    	}
    	else // Since there is a receipt number, update/edit the cleaning order
    	{
    	    strCommand = "UPDATE CleaningOrders " +
    			 "SET EmployeeNumber = '" +
    			 txtEmployeeNumber.Text + "', " +
    			" CustomerNumber = '" + txtCustomerPhone.Text + "', " +
    		" DateLeft = '" + dtpDateLeft.Value.ToString("d") + "', " +
    		" TimeLeft = '" + dtpTimeLeft.Value.ToString("t") + "', " +
    		" DateExpected = '" + dtpDateExpected.Value.ToString("d") + "', " +
    		" TimeExpected = '" + dtpTimeExpected.Value.ToString("t") + "', " +
    		" OrderStatus = '" + cbxOrderStatus.Text + "', " +
    		" DatePickedUp = '" + dtpDatePickedUp.Value.ToString("d") + "', " +
    		" TimePickedUp = '" + dtpDatePickedUp.Value.ToString("t") + "', " +
    		" UnitPriceShirts = '" + txtUnitPriceShirts.Text + "', " +
    		" QuantityShirts = '" + txtQuantityShirts.Text + "', " +
    		" SubTotalShirts = '" + txtSubTotalShirts.Text + "', " +
    		" UnitPricePants = '" + txtUnitPricePants.Text + "', " +
    		" QuantityPants = '" + txtQuantityPants.Text + "', " +
    		" SubTotalPants = '" + txtSubTotalPants.Text + "', " +
    		" Item1Name = '" + cbxItem1Name.Text + "', " +
    		" UnitPriceItem1 = '" + txtUnitPriceItem1.Text + "', " +
    		" QuantityItem1 = '" + txtQuantityItem1.Text + "', " +
    		" SubTotalItem1 = '" + txtSubTotalItem1.Text + "', " +
    		" Item2Name = '" + cbxItem2Name.Text + "', " +
    		" UnitPriceItem2 = '" + txtUnitPriceItem2.Text + "', " +
    		" QuantityItem2 = '" + txtQuantityItem2.Text + "', " +
    		" SubTotalItem2 = '" + txtSubTotalItem2.Text + "', " +
    		" Item3Name = '" + cbxItem3Name.Text + "', " +
    		" UnitPriceItem3 = '" + txtUnitPriceItem3.Text + "', " +
    		" QuantityItem3 = '" + txtQuantityItem3.Text + "', " +
    		" SubTotalItem3 = '" + txtSubTotalItem3.Text + "', " +
    		" Item4Name = '" + cbxItem4Name.Text + "', " +
    		" UnitPriceItem4 = '" + txtUnitPriceItem4.Text + "', " +
    		" QuantityItem4 = '" + txtQuantityItem4.Text + "', " +
    		" SubTotalItem4 = '" + txtSubTotalItem4.Text + "', " +
    		" CleaningTotal = '" + txtCleaningTotal.Text + "', " +
    		" TaxRate = '" + txtTaxRate.Text + "', " +
    		" TaxAmount = '" + txtTaxAmount.Text + "', " +
    		" NetPrice = '" + txtNetPrice.Text + "', " +
    		" Notes = '" + txtNotes.Text + "' " +
    		" WHERE CleaningOrderID = '" + txtCleaningOrderID.Text + "';";
    	}
    
    	SqlCommand cmdCleaningOrders = new SqlCommand(strCommand,
    	cnnCleaningOrders);
    
    	cnnCleaningOrders.Open();
    	cmdCleaningOrders.ExecuteNonQuery();
    
    	btnNewCleaningOrder_Click(sender, e);
        }
    }

45. On the form, double-click the Open button and implement the event as follows:
    

    private void btnOpen_Click(object sender, EventArgs e)
    {
        if (txtCleaningOrderID.Text.Length == 0)
        {
    	MessageBox.Show("To open a cleaning order, " +
    			"enter its receipt number and click Open.");
      	return;
        }
    
        using (SqlConnection cnnCleaningOrders =
    	new SqlConnection("Data Source=(local);" +
    	    		  "Database='GeorgetownDryCleaner1';" +
    			  "Integrated Security=SSPI;"))
        {
    	string strCleaningOrders =
    		"SELECT EmployeeNumber, CustomerNumber, DateLeft, " +
    		"TimeLeft, DateExpected, TimeExpected, " +
    		"OrderStatus, DatePickedUp, " +
    		"TimePickedUp, UnitPriceShirts, " +
    		"QuantityShirts, SubTotalShirts, " +
    		"UnitPricePants, QuantityPants, " +
    		"SubTotalPants, Item1Name, " +
    		"UnitPriceItem1, QuantityItem1, " +
    		"SubTotalItem1, Item2Name, " +
    		"UnitPriceItem2, QuantityItem2, " +
    		"SubTotalItem2, Item3Name, " +
    		"UnitPriceItem3, QuantityItem3, " +
    		"SubTotalItem3, Item4Name, " +
    		"UnitPriceItem4, QuantityItem4, " +
    		"SubTotalItem4, CleaningTotal, " +
    		"TaxRate, TaxAmount, NetPrice, Notes " +
    		"FROM CleaningOrders WHERE CleaningOrderID = '" +
    		txtCleaningOrderID.Text + "';";
        	SqlCommand cmdCleaningOrders =
    		new SqlCommand(strCleaningOrders, cnnCleaningOrders);
    	SqlDataAdapter daCleaningOrders = new SqlDataAdapter();
    
    
    	daCleaningOrders.SelectCommand = cmdCleaningOrders;
    	DataSet dsCleaningOrders = new DataSet("CleaningOrdersSet");
    	daCleaningOrders.Fill(dsCleaningOrders);
    
    	cnnCleaningOrders.Open();
    
    	for (int i = 0;
    	     i < dsCleaningOrders.Tables[0].Rows.Count; 
    	     i++)
    	{
    	    DataRow record = dsCleaningOrders.Tables[0].Rows[i];
    
    	    txtEmployeeNumber.Text = record[0].ToString();
    	    txtCustomerPhone.Text = record[1].ToString();
    
    	    dtpDateLeft.Value = DateTime.Parse(record[2].ToString());
    	    dtpTimeLeft.Value = DateTime.Parse(record[3].ToString());
    	    dtpDateExpected.Value = 
    		DateTime.Parse(record[4].ToString());
    	    dtpTimeExpected.Value = 
    		DateTime.Parse(record[5].ToString());
    
    	    cbxOrderStatus.Text = record[6].ToString();
    	
    	    dtpDatePickedUp.Value = 
    		DateTime.Parse(record[7].ToString());
    	    dtpTimePickedUp.Value = 
    		DateTime.Parse(record[8].ToString());
    
    	    txtUnitPriceShirts.Text = 
    		double.Parse(record[9].ToString()).ToString("F");
    	    txtQuantityShirts.Text = record[10].ToString();
    	    txtSubTotalShirts.Text = 
    		double.Parse(record[11].ToString()).ToString("F");
    
    	    txtUnitPricePants.Text = 
    		double.Parse(record[12].ToString()).ToString("F");
    	    txtQuantityPants.Text = record[13].ToString();
    	    txtSubTotalPants.Text = 
    		double.Parse(record[14].ToString()).ToString("F");
    
    	    cbxItem1Name.Text = record[15].ToString();
    	    txtUnitPriceItem1.Text = 
    		double.Parse(record[16].ToString()).ToString("F");
    	    txtQuantityItem1.Text = record[17].ToString();
    	    txtSubTotalItem1.Text = 
    		double.Parse(record[18].ToString()).ToString("F");
    
    	    cbxItem2Name.Text = record[19].ToString();
    	    txtUnitPriceItem2.Text = 
    		double.Parse(record[20].ToString()).ToString("F");
    	    txtQuantityItem2.Text = record[21].ToString();
    	    txtSubTotalItem2.Text = 
    		double.Parse(record[22].ToString()).ToString("F");
    
    	    cbxItem3Name.Text = record[23].ToString();
    	    txtUnitPriceItem3.Text = 
    		double.Parse(record[24].ToString()).ToString("F");
    	    txtQuantityItem3.Text = record[25].ToString();
    	    txtSubTotalItem3.Text = 
    		double.Parse(record[26].ToString()).ToString("F");
    
    	    cbxItem4Name.Text = record[27].ToString();
    	    txtUnitPriceItem4.Text = 
    		double.Parse(record[28].ToString()).ToString("F");
    	    txtQuantityItem4.Text = record[29].ToString();
    	    txtSubTotalItem4.Text = 
    		double.Parse(record[30].ToString()).ToString("F");
    
    	    txtCleaningTotal.Text = 
    		double.Parse(record[31].ToString()).ToString("F");
    	    txtTaxRate.Text = 
    		double.Parse(record[32].ToString()).ToString("F");
    	    txtTaxAmount.Text = 
    		double.Parse(record[33].ToString()).ToString("F");
    	    txtCleaningTotal.Text = 
    		double.Parse(record[34].ToString()).ToString("F");
    
    	    txtNotes.Text = record[35].ToString();
    
    	    txtEmployeeNumber_Leave(sender, e);
    	   txtCustomerPhone_Leave(sender, e);
    	}
        }
    }

46. Return to the Cleaning Orders form and click the unit price text box that corresponds to the pants
47. Press and hold Shift
48. Click the unit price text boxes for item 1, item 2, item 3, and item 4
49. Click each text box under the Qty label
50. Click the Tax Rate text box
51. Release Shift
52. In the Events section of the Properties window, double-click Leave and implement the event as follows:
    

    private void txtShirtsUnitPrice_Leave(object sender, EventArgs e)
    {
        double unitPriceShirts = 0.00, unitPricePants = 0.00,
               unitPriceItem1 = 0.00, unitPriceItem2 = 0.00,
               unitPriceItem3 = 0.00, unitPriceItem4 = 0.00;
               double subTotalShirts = 0.00, subTotalPants = 0.00,
               subTotalItem1 = 0.00, subTotalItem2 = 0.00,
               subTotalItem3 = 0.00, subTotalItem4 = 0.00;
        int qtyShirts = 1, qtyPants = 1, qtyItem1 = 1,
            qtyItem2 = 1, qtyItem3 = 1, qtyItem4 = 4;
        double cleaningTotal = 0.00, taxRate = 0.00,
               taxAmount = 0.00, netPrice = 0.00;
    
        // Retrieve the unit price of this item
        // Just in case the user types an invalid value,
        // we are using a try...catch
        try
        {
            unitPriceShirts = double.Parse(txtShirtsUnitPrice.Text);
        }
        catch (FormatException)
        {
            MessageBox.Show("The value you entered for the price of " +
                            "shirts is not valid" +
                            "\nPlease try again");
            return;
        }
    
        // Retrieve the number of this item
        // Just in case the user types an invalid value,
        // we are using a try...catch
        try
        {
            qtyShirts = int.Parse(txtShirtsQuantity.Text);
        }
        catch (FormatException)
        {
            MessageBox.Show("The value you entered for the number of " +
                            "shirts is not valid" +
                            "\nPlease try again");
            return;
        }
    
        try
        {
            unitPricePants = double.Parse(txtPantsUnitPrice.Text);
        }
        catch (FormatException)
        {
            MessageBox.Show("The value you entered for the price of " +
                            "pants is not valid" +
                            "\nPlease try again");
            return;
        }
    
        try
        {
            qtyPants = int.Parse(txtPantsQuantity.Text);
        }
        catch (FormatException)
        {
            MessageBox.Show("The value you entered for the number of " +
                            "pants is not valid" +
                            "\nPlease try again");
            return;
        }
    
        if ((cbxItem1Name.Text == "None") ||
            (cbxItem1Name.Text == ""))
        {
            qtyItem1 = 0;
            unitPriceItem1 = 0.00;
        }
        else
        {
            try
            {
                unitPriceItem1 = double.Parse(txtItem1UnitPrice.Text);
            }
            catch (FormatException)
            {
                MessageBox.Show("The value you entered for the price is not valid" +
                                "\nPlease try again");
                return;
            }
    
            try
            {
               qtyItem1 = int.Parse(txtItem1Quantity.Text);
                    }
                    catch (FormatException)
                    {
                        MessageBox.Show("The value you entered is not valid" +
                                        "\nPlease try again");
                        return;
                    }
                }
    
                if ((cbxItem2Name.Text == "None") ||
                (cbxItem2Name.Text == ""))
                {
                    qtyItem2 = 0;
                    unitPriceItem2 = 0.00;
                }
                else
                {
                    try
                    {
                        unitPriceItem2 = double.Parse(txtItem2UnitPrice.Text);
                    }
                    catch (FormatException)
                    {
                        MessageBox.Show("The value you entered for " +
                            "the price is not valid" +
                                        "\nPlease try again");
                        return;
                    }
    
                    try
                    {
                        qtyItem2 = int.Parse(txtItem2Quantity.Text);
                    }
                    catch (FormatException)
                    {
                        MessageBox.Show("The value you entered is not valid" +
                                        "\nPlease try again");
                        return;
                    }
                }
    
                if ((cbxItem3Name.Text == "None") ||
                (cbxItem3Name.Text == ""))
                {
                    qtyItem3 = 0;
                    unitPriceItem3 = 0.00;
                }
                else
                {
                    try
                    {
                        unitPriceItem3 = double.Parse(txtItem3UnitPrice.Text);
                    }
                    catch (FormatException)
                    {
                        MessageBox.Show("The value you entered for the " +
                            "price is not valid" +
                                        "\nPlease try again");
                        return;
                    }
    
                    try
                    {
                        qtyItem3 = int.Parse(txtItem3Quantity.Text);
                    }
                    catch (FormatException)
                    {
                        MessageBox.Show("The value you entered is not valid" +
                                        "\nPlease try again");
                        return;
                    }
                }
    
                if ((cbxItem4Name.Text == "None") || (cbxItem4Name.Text == ""))
                {
                    qtyItem4 = 0;
                    unitPriceItem4 = 0.00;
                }
                else
                {
                    try
                    {
                        unitPriceItem4 = double.Parse(txtItem4UnitPrice.Text);
                    }
                    catch (FormatException)
                    {
                        MessageBox.Show("The value you entered for the price is not valid" +
                                "\nPlease try again");
                        return;
                    }
                    try
                    {
                        qtyItem4 = int.Parse(txtItem4Quantity.Text);
                    }
                    catch (FormatException)
                    {
                        MessageBox.Show("The value you entered is not valid" +
                                "\nPlease try again");
                        return;
                    }
                }
    
        // Calculate the sub-total for this item
        subTotalShirts = qtyShirts * unitPriceShirts;
        subTotalPants = qtyPants * unitPricePants;
        subTotalItem1 = qtyItem1 * unitPriceItem1;
        subTotalItem2 = qtyItem2 * unitPriceItem2;
        subTotalItem3 = qtyItem3 * unitPriceItem3;
        subTotalItem4 = qtyItem4 * unitPriceItem4;
    
        // Calculate the total based on sub-totals
        cleaningTotal = subTotalShirts + subTotalPants + subTotalItem1 +
                        subTotalItem2 + subTotalItem3 + subTotalItem4;
    
        taxRate = double.Parse(txtTaxRate.Text);
        // Calculate the amount owed for the taxes
        taxAmount = cleaningTotal * taxRate / 100;
        // Add the tax amount to the total order
        netPrice = cleaningTotal + taxAmount;
    
        // Display the sub-total in the corresponding text box
        txtShirtsSubTotal.Text = subTotalShirts.ToString("F");
        txtPantsSubTotal.Text = subTotalPants.ToString("F");
        txtItem1SubTotal.Text = subTotalItem1.ToString("F");
        txtItem2SubTotal.Text = subTotalItem2.ToString("F");
        txtItem3SubTotal.Text = subTotalItem3.ToString("F");
        txtItem4SubTotal.Text = subTotalItem4.ToString("F");
    
        txtCleaningTotal.Text = cleaningTotal.ToString("F");
        txtTaxAmount.Text = taxAmount.ToString("F");
        txtNetPrice.Text = netPrice.ToString("F");
    
        SaveCleaningOrder();
    }

53. Return to the form and double-click the Close button
54. Implement its event as follows:
    

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

55. Execute the application
56. Create a few employees. Here are a few examples:
     
    
57. Create a few customers. Here are some examples:
     
    
58. Create a few cleaning orders. Here are examples:
     
    
59. Close the form and return to your programming environment
60. Execute the application again and open a few previously saved cleaning orders
61. After opening an order, update it. Here are examples:
     
62. Close the form and return to your programming environment