Data Binding With the Data Reader

Besides, the data grid view is a .NET object, not a Win32 control. As you may know already from your familiarity with Microsoft Windows, the operating system provides many more controls than that. Most users are more familiar with those controls and they would appreciate if the database is presented to them through these controls. The Windows controls in the .NET Framework were created to suit various types of controls, not just databases. Because they were made as broad as possible, the Windows controls are not readily made to display data. They need an intermediary object that can transmit data to them.

We know that we can use a data reader to read the value of a table. Once the values have been read, to access these values, you first call the Read() method of the class. The values read by the data adapter are stored in an indexed property of the class. When accessing each value, you must remember the order in which they are listed in the table.

As you read and access each value by its index, you can retrieve it and do what you want with it. For example you can assign it to a Windows control to display to the user. Here is an example:

private void btnLocate_Click(object sender, EventArgs e)
{
    using (SqlConnection Connect =
	new SqlConnection("Data Source=(local);" +
			  "Database='Exercise1';" +
			  "Integrated Security=SSPI;"))
    {
	string strItems =
	    "SELECT * FROM StoreItems WHERE [Stock Number] = '1482';";
	SqlCommand cmdEmployees =
		new SqlCommand(strItems, Connect);

	Connect.Open();

	SqlDataReader rdr = cmdEmployees.ExecuteReader();

	while (rdr.Read())
	    txtMerchandiseDescription.Text = rdr[1].ToString();
    }
}

When reading the records of a table, as mentioned already, the data reader reads one record at a time and moves to the next. Before moving to the next record, you can access the values stored in the current record. To help with this, the columns of the table being read are stored in a collection and each column can be referred to with a numeric index. The first column has an index of 1. The second column has an index of 2, and so on. To retrieve the actual data stored in a column, you may need to know the type of information the column is holding so you can read it accurately.

Depending on the data type that a column was created with, you can access it as follows:

When using one of the Get... or GetSql... methods, the compiler does not perform any conversion. This means that, before sending the data, you must convert the value read to the appropriate (and probably exact) format. For example, if you read a natural number from a column created with the tinyint data type, even though C# allows a short to be implicitly converted to an int, the compiler you use for your application would not perform or assume the conversion. For example, the value of a column created with tinyint must be read with GetByte() or GetSqlByte() and trying to use GetInt32() or GetSqlInt32() would throw an error.

1. Start Microsoft Visual Studio and create a new Windows Application named CollegeParkAutoRepair4
2. In the Solution Explorer, right-click Form1.cs and click Rename
3. Type RepairOrders.cs and press Enter twice
4. Design the form as follows:
    

   Control Name Text Additional Properties GroupBox   Order Identification   Label   Customer Name:   TextBox txtCustomerName     Label   Address:   TextBox txtAddress     Label   City:   TextBox txtCity     Label   State:   TextBox txtState     Label   ZIP Code:   TextBox txtZIPCode     Label   Make/Model:   TextBox txtMake     TextBox txtModel     Label   Year:   TextBox txtYear     Label   Problem Description:   TextBox txtProblemDescription   Scrollbars: Vertical Multiline: True GroupBox   Parts Used   Label   Part Name   Label   Unit Price   Label   Qty   Label   Sub Total   TextBox txtPart1Name     TextBox txtUnitPrice1 0.00 TextAlign: Right TextBox txtQuantity1 0 TextAlign: Right TextBox txtSubTotal1 0.00 TextAlign: Right TextBox txtPart2Name     TextBox txtUnitPrice2 0.00 TextAlign: Right TextBox txtQuantity2 0 TextAlign: Right TextBox txtSubTotal2 0.00 TextAlign: Right TextBox txtPart3Name     TextBox txtUnitPrice3 0.00 TextAlign: Right TextBox txtQuantity3 0 TextAlign: Right TextBox txtSubTotal3 0.00 TextAlign: Right TextBox txtPart4Name     TextBox txtUnitPrice4 0.00 TextAlign: Right TextBox txtQuantity4 0 TextAlign: Right TextBox txtSubTotal4 0.00 TextAlign: Right TextBox txtPart5Name     TextBox txtUnitPrice5 0.00 TextAlign: Right TextBox txtQuantity5 0 TextAlign: Right TextBox txtSubTotal5 0.00 TextAlign: Right GroupBox   Jobs Performed   Label   Job Description   Label   Price   TextBox txtJobDescription1     TextBox txtJobPrice1 0.00 TextAlign: Right TextBox txtJobDescription2     TextBox txtJobPrice2 0.00 TextAlign: Right TextBox txtJobDescription3     TextBox txtJobPrice3 0.00 TextAlign: Right TextBox txtJobDescription4     TextBox txtJobPrice4 0.00 TextAlign: Right TextBox txtJobDescription5     TextBox txtJobPrice5 0.00 TextAlign: Right GroupBox   Order Summary    Label    Total Parts:    TextBox txtTotalParts 0.00 TextAlign: Right Label     Total Labor:    TextBox txtTotalLabor 0.00 TextAlign: Right Label   Tax Rate:   TextBox txtTaxRate 7.75 TextAlign: Right Label   %   Label   Tax Amount:   TextBox txtTaxAmount 0.00 TextAlign: Right Label   Total Order:   TextBox txtTotalOrder 0.00 TextAlign: Right Label   Recommendations:   TextBox txtRecommendations   Scrollbars: Vertical Multiline: True  Button btnSave Save   Label   Receipt #:   TextBox txtReceiptNumber     Button btnOpen Open   Button btnNewRepairOrder New Repair Order   Button btnClose Close

5. Double-click an unoccupied area of the form and, to create the database, implement the 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 CollegeParkAutoRepair4
   {
       public partial class RepairOrders : Form
       {
   	public RepairOrders()
       	{
   	    InitializeComponent();
   	}
   
   	void CreateDatabase()
   	{
   	    using (SqlConnection conCPAR =
   		new SqlConnection("Data Source=(local); " +
   				  "Integrated Security='SSPI';"))
   	    {
   		string strCreateDatabase =
   		    "CREATE DATABASE CollegeParkAutoRepair1";
   
   		SqlCommand cmdCPAR = 
   		    new SqlCommand(strCreateDatabase,
   						    conCPAR);
   
   		conCPAR.Open();
   		cmdCPAR.ExecuteNonQuery();
   
   		MessageBox.Show("A database named " +
   		    	"CollegeParkAutoRepair1 has been created");
   	    }
   
   	    using (SqlConnection conCPAR =
   		new SqlConnection("Data Source=(local); " +
   			"Database='CollegeParkAutoRepair1'; " +
   			"Integrated Security='SSPI';"))
   	    {
   		string strCreateTable =
   		    "CREATE TABLE RepairOrders( " +
   		    "RepairOrderID int identity(100001, 1) NOT NULL, " +
   		    "CustomerName varchar(80) NOT NULL, " +
   		    "Address varchar(100) NOT NULL, " +
   		    "City varchar(50), State varchar(50), " +
   		    "ZIPCode varchar(50), CarMake varchar(50), " +
   		    "CarModel varchar(50), CarYear smallint, " +
   		    "ProblemDescription text, Part1Name varchar(80), " +
   		    "Part1UnitPrice money, Part1Quantity tinyint, " +
   		    "Part1SubTotal money, Part2Name varchar(80), " +
   		    "Part2UnitPrice money, Part2Quantity tinyint, " +
   		    "Part2SubTotal money, Part3Name varchar(80), " +
   		    "Part3UnitPrice money, Part3Quantity tinyint, " +
   		    "Part3SubTotal money, Part4Name varchar(80), " +
   		    "Part4UnitPrice money, Part4Quantity tinyint, " +
   		    "Part4SubTotal money, Part5Name varchar(80), " +
   		    "Part5UnitPrice money, Part5Quantity tinyint, " +
   		    "Part5SubTotal money, 
   		    "Job1Description varchar(80), Job1Price money, " +
   		    "Job2Description varchar(80), Job2Price money, " +
   		    "Job3Description varchar(80), Job3Price money, " +
   		    "Job4Description varchar(80), Job4Price money, " +
   		    "Job5Description varchar(80), Job5Price money, " +
   		    "TotalParts money, TotalLabor money, " +
   		    "TaxRate decimal(6,2), TaxAmount money, " +
   		    "TotalOrder money, Recommendations text, " +
   	"CONSTRAINT PK_RepairOrders PRIMARY KEY (RepairOrderID));";
   
   	SqlCommand cmdCPAR = new SqlCommand(strCreateTable, conCPAR);
   
   		conCPAR.Open();
   	    	cmdCPAR.ExecuteNonQuery();
   MessageBox.Show("A table named RepairOrders has been created");
   	    }
       	}
   
   	private void RepairOrders_Load(object sender, EventArgs e)
   	{
   	    CreateDatabase();
       	}
       }
   }

6. Execute the application to create the database and its table
7. Close the form and return to your programming environment
8. On the form, double-click the New Repair Order button and implement its event as follows:
   

   private void btnNewRepairOrder_Click(object sender, EventArgs e)
   {
       // This code is used to reset the form
       txtReceiptNumber.Text = "";
   
       txtCustomerName.Text = "";
       txtAddress.Text = ""; txtCity.Text = "";
       txtState.Text = ""; txtZIPCode.Text = "";
   
       txtMake.Text = ""; txtModel.Text = "";
       txtCarYear.Text = ""; txtProblemDescription.Text = "";
   
       txtPart1Name.Text = ""; txtUnitPrice1.Text = "0.00";
       txtQuantity1.Text = "0"; txtSubTotal1.Text = "0.00";
   
       txtPart2Name.Text = ""; txtUnitPrice2.Text = "0.00";
       txtQuantity2.Text = "0"; txtSubTotal2.Text = "0.00";
   
       txtPart3Name.Text = ""; txtUnitPrice3.Text = "0.00";
       txtQuantity3.Text = "0"; txtSubTotal3.Text = "0.00";
   
       txtPart4Name.Text = ""; txtUnitPrice4.Text = "0.00";
       txtQuantity4.Text = "0"; txtSubTotal4.Text = "0.00";
   
       txtPart5Name.Text = ""; txtUnitPrice5.Text = "0.00";
       txtQuantity5.Text = "0"; txtSubTotal5.Text = "0.00";
   
       txtJobDescription1.Text = ""; txtJobPrice1.Text = "0.00";
       txtJobDescription2.Text = ""; txtJobPrice2.Text = "0.00";
       txtJobDescription3.Text = ""; txtJobPrice3.Text = "0.00";
       txtJobDescription4.Text = ""; txtJobPrice4.Text = "0.00";
       txtJobDescription5.Text = ""; txtJobPrice5.Text = "0.00";
   
       txtRecommendations.Text = ""; txtTotalParts.Text = "0.00";
       txtTotalLabor.Text = "0.00"; txtTaxRate.Text = "7.75";
       txtTaxAmount.Text = "0.00"; txtTotalLabor.Text = "0.00";
   
       txtCustomerName.Focus();
   }

9. Change to Load event as follows:
   

   private void RepairOrders_Load(object sender, EventArgs e)
   {
       btnNewRepairOrder_Click(sender, e);
   }

10. Return to the form and click the first unit price text box
11. Press and hold Shift
12. Click the other unit price text boxes
13. Click each text box under the Qty label
14. Click each text box under Price (in the Jobs Performed group box)
15. Click the Tax Rate text box
16. Release Shift
17. In the Properties window, click the Events button and double-click Leave
18. Implement the event as follows:
    

    internal void CalculateOrder()
    {
        double UnitPrice1 = 0.00, UnitPrice2 = 0.00,
    	   UnitPrice3 = 0.00, UnitPrice4 = 0.00,
    	   UnitPrice5 = 0.00,
    	   SubTotal1, SubTotal2, SubTotal3,
    	   SubTotal4, SubTotal5, TotalParts;
        int Quantity1 = 0, Quantity2 = 0, Quantity3 = 0,
    	Quantity4 = 0, Quantity5 = 0;
        double JobPrice1 = 0.00, JobPrice2 = 0.00, JobPrice3 = 0.00,
    	   JobPrice4 = 0.00, JobPrice5 = 0.00, TotalLabor = 0.00;
        double TaxAmount, TotalOrder, TaxRate = 0.00;
    
        // Don't charge a part unless it is clearly identified
        if( txtPart1Name.Text == "")
        {
    	txtUnitPrice1.Text = "0.00";
    	txtQuantity1.Text = "0";
    	txtSubTotal1.Text = "0.00";
    	UnitPrice1 = 0.00;
        }
        else
        {
    	try
            {
    	    UnitPrice1 = double.Parse(this.txtUnitPrice1.Text);
        	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Unit Price");
    	    txtUnitPrice1.Text = "0.00";
    	    txtUnitPrice1.Focus();
    	}
    
    	try
    	{
    	    Quantity1 = int.Parse(this.txtQuantity1.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Quantity");
    	    txtQuantity1.Text = "0";
    	    txtQuantity1.Focus();
    	}
        }
    
        if (this.txtPart2Name.Text == "")
        {
    	txtUnitPrice2.Text = "0.00";
    	txtQuantity2.Text = "0";
    	txtSubTotal2.Text = "0.00";
    	UnitPrice2 = 0.00;
        }
        else
        {
    	try
        	{
    	    UnitPrice2 = double.Parse(this.txtUnitPrice2.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Unit Price");
    	    txtUnitPrice2.Text = "0.00";
    	    txtUnitPrice2.Focus();
    	}
    
    	try
    	{
    	    Quantity2 = int.Parse(this.txtQuantity2.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Quantity");
    	    txtQuantity2.Text = "0";
    	    txtQuantity2.Focus();
    	}
        }
    
        if (this.txtPart3Name.Text == "")
        {
    	txtUnitPrice3.Text = "0.00";
    	txtQuantity3.Text = "0";
    	txtSubTotal3.Text = "0.00";
    	UnitPrice3 = 0.00;
        }
        else
        {
    	try
    	{
    	    UnitPrice3 = double.Parse(this.txtUnitPrice3.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Unit Price");
    	    txtUnitPrice3.Text = "0.00";
    	    txtUnitPrice3.Focus();
    	}
    
    	try
    	{
    	    Quantity3 = int.Parse(this.txtQuantity3.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Quantity");
    	    txtQuantity3.Text = "0";
    	    txtQuantity3.Focus();
    	}
        }
    
        if (this.txtPart4Name.Text == "")
        {
    	txtUnitPrice4.Text = "0.00";
    	txtQuantity4.Text = "0";
    	txtSubTotal4.Text = "0.00";
    	UnitPrice4 = 0.00;
        }
        else
        {
    	try
    	{
    	    UnitPrice4 = double.Parse(this.txtUnitPrice4.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Unit Price");
    	    txtUnitPrice4.Text = "0.00";
    	    txtUnitPrice4.Focus();
    	}
    
    	try
    	{
    	    Quantity4 = int.Parse(this.txtQuantity4.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Quantity");
    	    txtQuantity4.Text = "0";
    	    txtQuantity4.Focus();
    	}
        }
    
        if (txtPart5Name.Text == "")
        {
    	txtUnitPrice5.Text = "0.00";
    	txtQuantity5.Text = "0";
    	txtSubTotal5.Text = "0.00";
    	UnitPrice5 = 0.00;
        }
        else
        {
    	try
    	{
    	    UnitPrice5 = double.Parse(this.txtUnitPrice5.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Unit Price");
    	    txtUnitPrice5.Text = "0.00";
    	    txtUnitPrice5.Focus();
    	}
    
    	try
    	{
    	    Quantity5 = int.Parse(this.txtQuantity5.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Quantity");
    	    txtQuantity5.Text = "0";
    	    txtQuantity5.Focus();
    	}
        }
    
        // Don't bill the customer for a job that is not specified
        if( txtJobDescription1.Text == "" )
        {
    	txtJobPrice1.Text = "0.00";
    	JobPrice1 = 0.00;
        }
        else
        {
    	try
    	{
    	    JobPrice1 = double.Parse(this.txtJobPrice1.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Job Price");
    	    txtJobPrice1.Text = "0.00";
    	    txtJobPrice1.Focus();
    	}
        }
    
        if (txtJobDescription2.Text == "")
        {
    	txtJobPrice2.Text = "0.00";
    	JobPrice2 = 0.00;
        }
        else
        {
    	try
    	{
    	    JobPrice2 = double.Parse(this.txtJobPrice2.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Job Price");
    	    txtJobPrice2.Text = "0.00";
    	    txtJobPrice2.Focus();
    	}
        }
    
        if (txtJobDescription3.Text == "")
        {
    	txtJobPrice3.Text = "0.00";
    	JobPrice3 = 0.00;
        }
        else
        {
    	try
    	{
    	    JobPrice3 = double.Parse(this.txtJobPrice3.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Job Price");
    	    txtJobPrice3.Text = "0.00";
    	    txtJobPrice3.Focus();
    	}
        }
    
        if (txtJobDescription4.Text == "")
        {
    	txtJobPrice4.Text = "0.00";
    	JobPrice4 = 0.00;
        }
        else
        {
    	try
    	{
    	    JobPrice4 = double.Parse(this.txtJobPrice4.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Job Price");
    	    txtJobPrice4.Text = "0.00";
    	    txtJobPrice4.Focus();
    	}
        }
    
        if (txtJobDescription5.Text == "")
        {
    	txtJobPrice5.Text = "0.00";
    	JobPrice5 = 0.00;
        }
        else
        {
    	try
    	{
    	    JobPrice5 = double.Parse(this.txtJobPrice5.Text);
    	}
    	catch (FormatException)
    	{
    	    MessageBox.Show("Invalid Job Price");
    	    txtJobPrice5.Text = "0.00";
    	    txtJobPrice5.Focus();
    	}
        }
    
        SubTotal1 = UnitPrice1 * Quantity1;
        SubTotal2 = UnitPrice2 * Quantity2;
        SubTotal3 = UnitPrice3 * Quantity3;
        SubTotal4 = UnitPrice4 * Quantity4;
        SubTotal5 = UnitPrice5 * Quantity5;
    
        txtSubTotal1.Text = SubTotal1.ToString("F");
        txtSubTotal2.Text = SubTotal2.ToString("F");
        txtSubTotal3.Text = SubTotal3.ToString("F");
        txtSubTotal4.Text = SubTotal4.ToString("F");
        txtSubTotal5.Text = SubTotal5.ToString("F");
    
        TotalParts = SubTotal1 + SubTotal2 + SubTotal3 +
    		 SubTotal4 + SubTotal5;
    
        TotalLabor = JobPrice1 + JobPrice2 + JobPrice3 +
    		 JobPrice4 + JobPrice5;
    
        try
        {
    	TaxRate = double.Parse(this.txtTaxRate.Text);
        }
        catch (FormatException)
        {
    	MessageBox.Show("Invalid Tax Rate");
    	txtTaxRate.Text = "7.75";
    	txtTaxRate.Focus();
        }
    
        double TotalPartsAndLabor = TotalParts + TotalLabor;
        TaxAmount = TotalPartsAndLabor * TaxRate / 100;
        TotalOrder = TotalPartsAndLabor + TaxAmount;
    
        txtTotalParts.Text = TotalParts.ToString("F");
        txtTotalLabor.Text = TotalLabor.ToString("F");
        txtTaxAmount.Text = TaxAmount.ToString("F");
        txtTotalOrder.Text = TotalOrder.ToString("F");
    }
    
    private void txtUnitPrice1_Leave(object sender, EventArgs e)
    {
        CalculateOrder();
    } 

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

    private void btnSave_Click(object sender, EventArgs e)
    {
        string strCommand = "";
    
        using (SqlConnection cnnRepairOrders =
    	new SqlConnection("Data Source=(local);" +
    			  "Database='CollegeParkAutoRepair1';" +
    		 	  "Integrated Security=SSPI;"))
        {
    	// If the Receipt Number is empty, it appears that
    	// the user/clerk wants to create a new cleaning order
    	if( txtReceiptNumber.Text == "" )
    	{
    	    strCommand = "INSERT INTO RepairOrders( " +
    		"CustomerName, Address, City, " +
    		"State, ZIPCode, CarMake, " +
    		"CarModel, CarYear, ProblemDescription, " +
    		"Part1Name, Part1UnitPrice, Part1Quantity, " +
    		"Part1SubTotal, Part2Name, Part2UnitPrice, " +
    		"Part2Quantity, Part2SubTotal, Part3Name, " +
    		"Part3UnitPrice, Part3Quantity, Part3SubTotal, " +
    		"Part4Name, Part4UnitPrice, Part4Quantity, " +
    		"Part4SubTotal, Part5Name, Part5UnitPrice, " +
    		"Part5Quantity, Part5SubTotal, Job1Description, " +
    		"Job1Price, Job2Description, Job2Price, " +
    		"Job3Description, Job3Price, Job4Description, " +
    		"Job4Price, Job5Description, Job5Price, " +
    		"Recommendations, TotalParts, TotalLabor, " +
    		"TaxRate, TaxAmount, TotalOrder) " +
    		"VALUES('" + txtCustomerName.Text + "', '" +
    		txtAddress.Text + "', '" + txtCity.Text +
    		"', '" + txtState.Text + "', '" +
    		txtZIPCode.Text + "', '" + txtMake.Text +
    		"', '" + txtModel.Text + "', '" +
    		txtCarYear.Text + "', '" +
    		txtProblemDescription.Text + "', '" +
    	txtPart1Name.Text + "', '" + txtUnitPrice1.Text + "', '" +
    	txtQuantity1.Text + "', '" + txtSubTotal1.Text + "', '" +
    	txtPart2Name.Text + "', '" + txtUnitPrice2.Text + "', '" +
    	txtQuantity2.Text + "', '" + txtSubTotal2.Text + "', '" +
    	txtPart3Name.Text + "', '" + txtUnitPrice3.Text + "', '" +
    	txtQuantity3.Text + "', '" + txtSubTotal3.Text + "', '" +
    	txtPart4Name.Text + "', '" + txtUnitPrice4.Text + "', '" +
    	txtQuantity4.Text + "', '" + txtSubTotal4.Text + "', '" +
    	txtPart5Name.Text + "', '" + txtUnitPrice5.Text + "', '" +
    	txtQuantity5.Text + "', '" + txtSubTotal5.Text + "', '" +
    	txtJobDescription1.Text + "', '" + txtJobPrice1.Text + "', '" +
    	txtJobDescription2.Text + "', '" + txtJobPrice2.Text + "', '" +
    	txtJobDescription3.Text + "', '" + txtJobPrice3.Text + "', '" +
    	txtJobDescription4.Text + "', '" + txtJobPrice4.Text + "', '" +
    	txtJobDescription5.Text + "', '" + txtJobPrice5.Text + "', '" +
    	txtRecommendations.Text + "', '" + txtTotalParts.Text + "', '" +
    	txtTotalLabor.Text + "', '" + txtTaxRate.Text + "', '" +
    	txtTaxAmount.Text + "', '" + txtTotalOrder.Text + "');";
    	}
    	else // Since there is a receipt number, update/edit the cleaning order
    	{
    	    strCommand = "UPDATE CleaningOrders " +
    		"SET CustomerName = '" + txtCustomerName.Text + "', " +
    		"    Address = '" + txtAddress.Text + "', " +
    		"    City = '" + txtCity.Text + "', " +
    		"    State = '" + txtState.Text + "', " +
    		"    ZIPCode = '" + txtZIPCode.Text + "', " +
    		"    CarMake = '" + txtMake.Text + "', " +
    		"    CarModel = '" + txtModel.Text + "', " +
    		"    CarYear = '" + txtCarYear.Text + "', " +
    	" ProblemDescription = '" + txtProblemDescription.Text + "', " +
    		"    Part1Name = '" + txtPart1Name.Text + "', " +
    		"    Part1UnitPrice = '" + txtUnitPrice1.Text + "', " +
    		"    Part1Quantity = '" + txtQuantity1.Text + "', " +
    		"    Part1SubTotal = '" + txtSubTotal1.Text + "', " +
    		"    Part2Name = '" + txtPart2Name.Text + "', " +
    		"    Part2UnitPrice = '" + txtUnitPrice2.Text + "', " +
    		"    Part2Quantity = '" + txtQuantity2.Text + "', " +
    		"    Part2SubTotal = '" + txtSubTotal2.Text + "', " +
    		"    Part3Name = '" + txtPart3Name.Text + "', " +
    		"    Part3UnitPrice = '" + txtUnitPrice3.Text + "', " +
    		"    Part3Quantity = '" + txtQuantity3.Text + "', " +
    		"    Part3SubTotal = '" + txtSubTotal3.Text + "', " +
    		"    Part4Name = '" + txtPart4Name.Text + "', " +
    		"    Part4UnitPrice = '" + txtUnitPrice4.Text + "', " +
    		"    Part4Quantity = '" + txtQuantity4.Text + "', " +
    		"    Part4SubTotal = '" + txtSubTotal4.Text + "', " +
    		"    Part5Name = '" + txtPart5Name.Text + "', " +
    		"    Part5UnitPrice = '" + txtUnitPrice5.Text + "', " +
    		"    Part5Quantity = '" + txtQuantity5.Text + "', " +
    		"    Part5SubTotal = '" + txtSubTotal5.Text + "', " +
    		"    Job1Description = '" + txtJobDescription1.Text + "', " +
    		"    Job1Price = '" + txtJobDescription1.Text + "', " +
    		"    Job2Description = '" + txtJobDescription2.Text + "', " +
    		"    Job2Price = '" + txtJobDescription2.Text + "', " +
    		"    Job3Description = '" + txtJobDescription3.Text + "', " +
    		"    Job3Price = '" + txtJobDescription3.Text + "', " +
    		"    Job4Description = '" + txtJobDescription4.Text + "', " +
    		"    Job4Price = '" + txtJobDescription4.Text + "', " +
    		"    Job5Description = '" + txtJobDescription5.Text + "', " +
    		"    Job5Price = '" + txtJobDescription5.Text + "', " +
    		"    TotalParts = '" + txtTotalParts.Text + "', " +
    		"    TotalLabor = '" + txtTotalLabor.Text + "', " +
    		"    TaxRate = '" + txtTaxRate.Text + "', " +
    		"    TaxAmount = '" + txtTaxAmount.Text + "', " +
    		"    TotalOrder = '" + txtTotalOrder.Text + "' " +
    		"    WHERE RepairOrderID = '" + txtReceiptNumber.Text + "';";
    	}
    
    	SqlCommand cmdCleaningOrders = new SqlCommand(strCommand,
    						      cnnRepairOrders);
    
    	cnnRepairOrders.Open();
    	cmdCleaningOrders.ExecuteNonQuery();
    
    	btnNewRepair_Click(sender, e);
        }
    } 

21. Return to the form and double-click the Open button
22. Implement its event as follows:
    

    private void btnOpen_Click(object sender, EventArgs e)
    {
        string strReceiptNumber = txtReceiptNumber.Text;
    
        if (strReceiptNumber.Length == 0 )
        {
    	MessageBox.Show("You open a repair order, " +
    			"enter its receipt number and click Open.");
    	return;
        }
    
        using (SqlConnection conDatabase = new
    	SqlConnection("Data Source=(local);" +
    		      "Database='CollegeParkAutoRepair1';" +
    		      "Integrated Security=yes"))
        {
    	string strFindRepair =
    	    "SELECT * FROM RepairOrders WHERE RepairOrderID = '" +
    	    strReceiptNumber + "'";
    	SqlCommand cmdDatabase = new
    	SqlCommand(strFindRepair, conDatabase);
    
    	conDatabase.Open();
    
    	SqlDataReader rdrRepairOrder;
    	rdrRepairOrder = cmdDatabase.ExecuteReader();
    
    	while (rdrRepairOrder.Read())
    	{
    	    txtCustomerName.Text = rdrRepairOrder.GetString(1);
    	    txtAddress.Text = rdrRepairOrder.GetString(2);
    	    txtCity.Text = rdrRepairOrder.GetString(3);
    	    txtState.Text = rdrRepairOrder.GetString(4);
    	    txtZIPCode.Text = rdrRepairOrder.GetString(5);
    	    txtMake.Text = rdrRepairOrder.GetString(6);
    	    txtModel.Text = rdrRepairOrder.GetString(7);
    	    txtCarYear.Text = 
    		rdrRepairOrder.GetSqlInt16(8).ToString();
    	    txtProblemDescription.Text = rdrRepairOrder.GetString(9);
    
    	    txtPart1Name.Text = rdrRepairOrder.GetString(10);
    	    txtUnitPrice1.Text = 
    		rdrRepairOrder.GetSqlMoney(11).ToString();
    	    txtQuantity1.Text = 
    		rdrRepairOrder.GetSqlByte(12).ToString();
    	    txtSubTotal1.Text = 
    		rdrRepairOrder.GetSqlMoney(13).ToString();
    
    	    txtPart2Name.Text = rdrRepairOrder.GetString(14);
    	    txtUnitPrice2.Text = 
    		rdrRepairOrder.GetSqlMoney(15).ToString();
    	    txtQuantity2.Text = 
    		rdrRepairOrder.GetSqlByte(16).ToString();
    	    txtSubTotal2.Text = 
    		rdrRepairOrder.GetSqlMoney(17).ToString();
    
    	    txtPart3Name.Text = rdrRepairOrder.GetString(18);
    	    txtUnitPrice3.Text = 
    		rdrRepairOrder.GetSqlMoney(19).ToString();
    	    txtQuantity3.Text = 
    		rdrRepairOrder.GetSqlByte(20).ToString();
    	    txtSubTotal3.Text = 
    		rdrRepairOrder.GetSqlMoney(21).ToString();
    
    	    txtPart4Name.Text = rdrRepairOrder.GetString(22);
    	    txtUnitPrice4.Text = 
    		rdrRepairOrder.GetSqlMoney(23).ToString();
    	    txtQuantity4.Text = 
    		rdrRepairOrder.GetSqlByte(24).ToString();
    	    txtSubTotal4.Text = 
    		rdrRepairOrder.GetSqlMoney(25).ToString();
    
    	    txtPart5Name.Text = rdrRepairOrder.GetString(26);
    	    txtUnitPrice5.Text = 
    		rdrRepairOrder.GetSqlMoney(27).ToString();
    	    txtQuantity5.Text = 
    		rdrRepairOrder.GetSqlByte(28).ToString();
    	    txtSubTotal5.Text = 
    		rdrRepairOrder.GetSqlMoney(29).ToString();
    
    	    txtJobDescription1.Text = rdrRepairOrder.GetString(30);
    	    txtJobPrice1.Text = 
    		rdrRepairOrder.GetSqlMoney(31).ToString();
    	    txtJobDescription2.Text = rdrRepairOrder.GetString(32);
    	    txtJobPrice2.Text = 
    		rdrRepairOrder.GetSqlMoney(33).ToString();
    	    txtJobDescription3.Text = rdrRepairOrder.GetString(34);
    	    txtJobPrice3.Text = 
    		rdrRepairOrder.GetSqlMoney(35).ToString();
    	    txtJobDescription4.Text = rdrRepairOrder.GetString(36);
    	    txtJobPrice4.Text = 
    		rdrRepairOrder.GetSqlMoney(37).ToString();
    	    txtJobDescription5.Text = rdrRepairOrder.GetString(38);
    	    txtJobPrice5.Text = 
    		rdrRepairOrder.GetSqlMoney(39).ToString();
    
    	    txtTotalParts.Text = 
    		rdrRepairOrder.GetSqlMoney(40).ToString();
    	    txtTotalLabor.Text = 
    		rdrRepairOrder.GetSqlMoney(41).ToString();
    	    txtTaxRate.Text = 
    		rdrRepairOrder.GetSqlDecimal(42).ToString();
    	    txtTaxAmount.Text = 
    		rdrRepairOrder.GetSqlMoney(43).ToString();
    	    txtTotalOrder.Text = 
    		rdrRepairOrder.GetSqlMoney(44).ToString();
    
    	    txtRecommendations.Text = rdrRepairOrder.GetString(45);
    	}
    
    	rdrRepairOrder.Close();
        }
    } 

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

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

25. Execute the application
26. Create a few repair orders. Here are two examples:
     
27. Close the form and return to your programming environment
28. Execute the application again and open a few previously saved cleaning orders