Microsoft Visual C#: ADO.NET and the Table Adapters

1. Open the Fun Department Store 1 file (FunDS2.txt)
2. Select its content and copy it
3. Start Microsoft SQL Server and connect to the server
4. Create a Query window and paste the code in it
5. To create the database, press F5
6. Start Microsoft Visual Studio
7. To create a new application, on the main menu, click File -> New Project...
8. In the middle list, click Windows Forms Application
9. Change the Name to FunDepartmentStore1
10. Click OK
11. In the Solution Explorer, right-click Form1.cs and click Rename
12. Type FunDepartmentStore.cs and press Enter
13. Design the form as follows:
     

    Control Text Name Button Process a Customer Order btnProcessOrder Button Create a New Store Item btnCreateStoreItem Button View Current Store Inventory btnCurrentInventory Button Manage a Store Items btnManageStoreItem Button Close btnClose

14. To add a new form, on the menu, click Project -> Add Windows Form...
15. Set the Name to ShoppingSession and click Add
16. From the Components section of the Toolbox, click Timer and click the form
17. Design the form as follows:
     

    Control Text Name Other Properties Form Fun Department Store - Shopping Session   ShowInTaskbar: False StartPosition: CenterScreen Panel     BorderStyle: Fixed3D Label Item #   Font: Times New Roman, 20.25pt, style=Bold ForeColor: Blue Label Item Name/Description   Font: Times New Roman, 20.25pt, style=Bold ForeColor: Blue Label Size   Font: Times New Roman, 20.25pt, style=Bold ForeColor: Blue Label Unit Price   Font: Times New Roman, 20.25pt, style=Bold ForeColor: Blue TextBox   txtItemNumber Font: Times New Roman, 20.25pt TextAlign: Center TextBox   txtItemName Font: Times New Roman, 20.25pt TextBox   txtItemSize Font: Times New Roman, 20.25pt TextBox   txtUnitPrice Font: Times New Roman, 20.25pt TextAlign: Right ListView   lvwShoppingSession Anchor: Top, Bottom, Left, Right Font: Times New Roman, 20.25pt FullRowSelect: True GridLines: True View: Details   Columns (Name) Text TextAlign Width colItemNumber Item #   100 colItemName Item Name/Description   446 colItemSize Size Center 100 colUnitPrice Unit Price Right 124 Label Type of Payment:   Font: Times New Roman, 20.25pt, style = Bold ForeColor: Blue ComboBox   cbxCurrencyType Font: Times New Roman, 20.25pt, style = Bold Items: Cash           Check           Visa           Master Card           Store Card Label Order Total:   Font: Times New Roman, 20.25pt, style = Bold ForeColor: Blue TextBox   txtOrderTotal Anchor: Bottom, Right Font: Times New Roman, 20.25pt, style = Bold Text: 0.00 TextAlign: Right Label Order Time:   Font: Times New Roman, 20.25pt, style = Bold ForeColor: Blue Label Order Date:   Font: Times New Roman, 20.25pt, style = Bold ForeColor: Blue Label Amount Tended:   Font: Times New Roman, 20.25pt, style = Bold ForeColor: Blue TextBox   txtAmountTended Anchor: Bottom, Right Font: Times New Roman, 20.25pt, style = Bold Text: 0.00 TextAlign: Right Button   btnSubmitOrder Anchor: Bottom, Left, Right Font: Times New Roman, 20.25pt, style = Bold Label Change:   Font: Times New Roman, 20.25pt, style=Bold ForeColor: Blue TextBox   txtChange Anchor: Bottom, Right Font: Times New Roman, 20.25pt, style=Bold Text: 0.00 TextAlign: Right Label Receipt #:   Font: Times New Roman, 20.25pt, style=Bold ForeColor: Blue TextBox   txtReceiptNumber Anchor: Bottom, Right Font: Times New Roman, 20.25pt, style=Bold Button   btnCancelOrder Anchor: Bottom, Left, Right Font: Times New Roman, 20.25pt, style=Bold Button   btnClose Anchor: Bottom, Left, Right Font: Times New Roman, 20.25pt, style=Bold Panel     BorderStyle: Fixed3D Label   lblDate Font: Times New Roman, 20.25pt, style=Bold ForeColor: Blue Label   lblTime Font: Times New Roman, 20.25pt, style=Bold ForeColor: Blue Timer   tmrDateTime Enabled: True

18. Double-click the timer
19. Implement its event as follows:

    private void tmrDateTime_Tick(object sender, EventArgs e)
    {
        lblDate.Text = DateTime.Today.ToLongDateString();
        lblTime.Text = DateTime.Now.ToLongTimeString();
    }

We already know how to visually create a data set, by adding a new data source from either the main menu under Data or the Data Sources window. We have seen various ways of doing this using the Data Source Configuration Wizard. When the wizard ends, a class is generated. Remember that in the last page of the wizard, you select one or more tables you would use from the database. When the wizard ends, it creates a class for each table.

The class is based on the TypedTableBase class from the System.Data namespace. Here is an example of how such a class starts:

public partial class EmployeesDataTable : 
			global::System.Data.TypedTableBase<EmployeesRow>
{

}

Inside the class for the table, a DataColumn variable is declared for each column of the table. Inside the class for the new data set, the wizard declares a variable for each table class.

Besides classes for the tables, the wizard also generates classes referred to as table adapters. A table adapter class is generated for each table. The class is derived from Component. Here is an example:

public partial class EmployeesTableAdapter : global::System.ComponentModel.Component
{

}

The class includes various properties and methods that can be used for database management and maintenance.

1. On the main menu, click Data -> Add New Data Source...
2. On the first page of the wizard, make sure Database is selected and click Next
3. In the second page of the wizard, make sure Dataset is selected and click Next
4. In the third page of the wizard, click New Connection...
   If the Choose Data Source dialog box comes up, click Microsoft SQL Server and click Continue
5. In the Server Name combo box, select the server or type (local)
6. In the Select or Enter a Database Name combo box, select FunDS1
7. Click Test Connection
8. Click OK twice
9. On the Data Source Configuration Wizard, make sure the new connection is selected
   Click the + button of Connection String
10. Click Next
11. Change the connection string to csFunDS and click Next
12. Click the check box of Tables (to select all tables)
13. Change the name of the data set to dsFunDS
     
    
    
14. Click Finish
15. In the Solution Explorer, double-click dsFunDS.Designer.cs to open and view the file
16. Execute the application
17. After viewing the main form, close it
18. Display the ShoppingSession form
19. In the top section of the Toolbox, click dsFunDS
20. Click the form
21. In the top section of the Toolbox, click CustomersOrdersTableAdapter
22. Click the form
23. In the Properties window, change its name to taCustomersOrders
24. In the top section of the Toolbox, click ReceiptsSummariesTableAdapter
25. Click the form
26. In the Properties window, change its name to taReceiptsSummaries
27. In the top section of the Toolbox, click StoreItemsTableAdapter
28. Click the form
29. In the Properties window, change its name to taStoreItems

When creating a table adapter, if its corresponding table has records, it gets equipped with them and you can use them as you see fit. To pass its records to a table, the generated table adapter is equipped with a method named Fill. This method takes as argument the table class that was generated, it fills it with the records, and returns it. To assist you with getting the records, the table adapter class is equipped with a method named GetData. This method takes no argument and returns an object of the table class type that was generated. Here is an example of calling this method:

private void btnLoadCustomers_Click(object sender, EventArgs e)
{
    dgvCustomers.DataSource = taCustomers.GetData();
}

Remember that the GetData() method returns a table adapter class that inherits from the DataTable. Thanks to this, GetData() gives you access to regular operations performed on a table.

1. To add another form, on the main menu, click Project -> Add Windows Form
2. Set the Name to CurrentStoreInventory
3. Click Add
4. In the top section of the Toolbox, click dsFunDS
5. Click the form
6. In the top section of the Toolbox, click StoreItemsTableAdapter
7. Click the form
8. In the Properties window, change its name to taStoreItems
9. Design the form as follows: 

   Control	Text	Name	Other Properties
   ListView		lvwStoreItems	Anchor: Top, Bottom, Left, Right FullRowSelect: True GridLines: True View: Details
   	Columns	(Name) Text TextAlign Width colIndex Index     colItemNumber Item #   80 colManufacturer Manufacturer   100 colCategory Category     colSubCategory Sub-Category   80 colItemName Item Name/Description   200 colItemSize Size Center 100 colUnitPrice Unit Price Right   colSaleStatus Status
   Button	Show Store Items Inventory	btnShowCurrentInventory	Anchor: Bottom, Left, Right
   Button	Close	btnClose	Anchor: Bottom, Right

10. Double-click the Show Store Items Inventory button and implement its Click event as follows:
    

    private void btnShowCurrentInventory_Click(object sender, EventArgs e)
    {
        for (int i = 0; i < taStoreItems.GetData().Rows.Count; i++)
        {
            DataRow rcdStoreItem = taStoreItems.GetData().Rows[i];
    
            ListViewItem lviStoreItem = new ListViewItem((i + 1).ToString());
            lviStoreItem.SubItems.Add(rcdStoreItem["ItemNumber"].ToString());
            lviStoreItem.SubItems.Add(rcdStoreItem["Manufacturer"].ToString());
            lviStoreItem.SubItems.Add(rcdStoreItem["Category"].ToString());
            lviStoreItem.SubItems.Add(rcdStoreItem["SubCategory"].ToString());
            lviStoreItem.SubItems.Add(rcdStoreItem["ItemName"].ToString());
            lviStoreItem.SubItems.Add(rcdStoreItem["ItemSize"].ToString());
            lviStoreItem.SubItems.Add(
                double.Parse(rcdStoreItem["UnitPrice"].ToString()).ToString("F"));
            lviStoreItem.SubItems.Add(rcdStoreItem["SaleStatus"].ToString());
            lvwStoreItems.Items.Add(lviStoreItem);
        }
    }

11. Return to the form and double-click the Close button
12. Implement it as follows:

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

13. Close the CurrentStoreInventory.cs tab
14. Close the CurrentStoreInventory.cs [Design] tab
15. Show the Central form
16. Double-click the View Current Store Inventory
17. Implement its Click event as follows:

    private void btnCurrentInventory_Click(object sender, EventArgs e)
    {
        CurrentStoreInventory csi = new CurrentStoreInventory();
        csi.ShowDialog();
    }

18. Press Ctrl + F5 to execute
19. Open the Current Inventory form
20. Click the Show Store Items Inventory button
21. Close the forms and return to your programming environment

Among the characteristics that a table adapter provides is a connection object. To give you access to the connection the table adapter is using, the generated class is equipped with a property named Connection and that is of type SqlConnection. Here is an example of getting that connection: private void btnConnection_Click(object sender, EventArgs e) { MessageBox.Show(taCustomers.Connection.ToString()); }

You can use the connection object to get such information as the name of the server or the connection string. Here is an example:

private void btnConnection_Click(object sender, EventArgs e)
{
    MessageBox.Show(taCustomers.Connection.ConnectionString);
}

The generated table adapter class is equipped with a property named Adapter. This property is of type SqlDataAdapter. It gives you access to some operations that can be performed on a data adapter. Once a table contains records, you may be interested in finding a value. To do this, you can use Transact-SQL through the Adapter property of the table class that was genereated. Remember that the Adapter property is of type SqlDataAdapeter. This means that it is equipped with the SelectCommand property that itself is of type SqlCommand. The SqlCommand class is equipped with the CommandText property. This is the property you would assign the Transact-SQL statement to.

We mentioned that the table class generated by the wizard provides the normal characteristics of a DataTable. This means that it gives you access to the records of the table. This is possible because the class inherits the Rows property from its ancestor. As you may recall, the DataTable.Rows property is of type DataRowCollection.

To locate a record, you can use a column name. To support this, the data row is equipped with an Item indexed property that takes a column name as parameter.

1. Display the ShoppingSession form
2. Double-click the Cancel/Reset Current Order button
3. Implement its 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 DepartmentStore1
   {
       public partial class ShoppingSession : Form
       {
           // This variable will represent the receipt number
           int receiptNumber;
           // This variable will represent the total value of the shopping 
           double totalOrder;
           
           public ShoppingSession()
           {
               InitializeComponent();
           }
   
           private void btnCancelOrder_Click(object sender, EventArgs e)
           {
               // First reset the form
               totalOrder = 0.00;
               txtItemNumber.Text = "";
               txtItemName.Text = "";
               txtUnitPrice.Text = "0.00";
               lvwShoppingSession.Items.Clear();
               txtOrderTotal.Text = "0.00";
               txtAmountTended.Text = "0.00";
               txtChange.Text = "0.00";            
   
               if (taCustomersOrders.GetData().Rows.Count > 0){
                   foreach (DataRow rcdCustomerOrder in taCustomersOrders.GetData().Rows)
                       receiptNumber = int.Parse(rcdCustomerOrder["ReceiptNumber"].ToString()) + 1;
               }
   
               txtReceiptNumber.Text = receiptNumber.ToString();
           }    
       }
   }

4. Return to the Shopping Session form and double-click an unoccupied area of its body (outside of any group box)
5. Implement its event as follows:

   private void ShoppingSession_Load(object sender, EventArgs e)
   {
       totalOrder = 0.00;
       receiptNumber = 100000;
       btnCancelOrder_Click(sender, e);
   }

The table adapter provides many flexible methods and properties that allow you to get various pieces of information about its table. For example, you can use it to locate a record using various techniques such as the index of a record followed by the name of a column. Here is an example that gets to the second record and its column named FullName:

private void btnConnection_Click(object sender, EventArgs e)
{
    MessageBox.Show(taCustomers.GetData().Rows[2]["FullName"].ToString());
}

The DataRowCollection class is equipped with a method named Find. You can call this method through the table adapter variable to locate a record. Here is an example:

private void btnConnection_Click(object sender, EventArgs e)
{
    MessageBox.Show(taCustomers.GetData().Rows.Find("608208")["AccountNumber"].ToString());
}

1. Return to the ShoppingSession form (the ShoppingSession.cs [Design] tab)
2. On the form, click the Item # text box
3. In the Properties window, click Events
4. Double-click Leave
5. Implement the event as follows:

   private void txtItemNumber_Leave(object sender, EventArgs e)
   {
       double unitPrice = 0.00;
   
       if (txtItemNumber.Text == "")
       {
           return;
       }
   
       try
       {
           DataRow rcdStoreItem = 
   	    taStoreItems.GetData().Rows.Find(txtItemNumber.Text);
   
           txtItemName.Text = rcdStoreItem["ItemName"].ToString();
           txtItemSize.Text = rcdStoreItem["ItemSize"].ToString();
           unitPrice = double.Parse(rcdStoreItem["UnitPrice"].ToString());
   
           totalOrder = totalOrder + unitPrice;
           txtUnitPrice.Text = unitPrice.ToString("F");
   
           ListViewItem lviStoreItem = new ListViewItem(txtItemNumber.Text);
           lviStoreItem.SubItems.Add(txtItemName.Text);
           lviStoreItem.SubItems.Add(txtItemSize.Text);
           lviStoreItem.SubItems.Add(unitPrice.ToString("F"));
           lvwShoppingSession.Items.Add(lviStoreItem);
   
           txtOrderTotal.Text = totalOrder.ToString("F");
   
           txtItemNumber.Text = "";
           txtItemName.Text = "";
           txtItemSize.Text = "";
           txtUnitPrice.Text = "0.00";
           txtItemNumber.Focus();
       }
       catch (NullReferenceException)
       {
           MessageBox.Show("There is no store item with that number");
       }
       catch (IndexOutOfRangeException)
       {
           MessageBox.Show("There is no store item with that number");
       }
   }

6. Return to the Shopping Session form and click the Amount Tended text box
7. In the Events section of the Properties window, double-click Leave
8. Implement the event as follows:

   private void txtAmountTended_Leave(object sender, EventArgs e)
   {
       double totalOrder = 0.00;
       double amountTended = 0.00;
       double change = 0.00;
   
       try
       {
           totalOrder = double.Parse(txtOrderTotal.Text);
           amountTended = double.Parse(txtAmountTended.Text);
           change = amountTended - totalOrder;
   
           txtChange.Text = change.ToString("F");
           btnSubmitOrder.Focus();
       }
       catch (FormatException)
       {
           MessageBox.Show("Invalid Value!",
                           "Fun Department Store",
                           MessageBoxButtons.OK, MessageBoxIcon.Information);
       }
   }

9. Return to the Central form
10. Double-click the Process a Customer Order
11. Implement its Click event as follows:

    private void btnProcessOrder_Click(object sender, EventArgs e)
    {
        ShoppingSession shop = new ShoppingSession();
        shop.ShowDialog();
    }

12. To create a new form, on the main menu, click Project -> Add Windows Form...
13. Set the Name to ManageStoreItem and click Add
14. In the top section of the Toolbox, click dsFunDS
15. Click the form
16. In the top section of the Toolbox, click StoreItemsTableAdapter
17. Click the form
18. In the Properties window, change its name to taStoreItems
19. Design the form as follows:
     

    Control Text Name Other Properties Label Item #:     TextBox   txtItemNumber   Button Find btnFind   Label Manufacturer:     TextBox   txtManufacturer   Label Category:     ComboBox   cbxCategories Items: Men          Girls          Boys          Babies          Women          Other Label Sub-Category:     ComboBox   cbxSubCategories Items: Skirts Pants Shirts Shoes Beauty Dresses Clothing Sweater Watches Handbags Miscellaneous Label Item Name:     TextBox   txtItemName   Label Size:     TextBox   txtItemSize   Label Unit Price:     TextBox   txtUnitPrice Text: 0.00 TextAlign: Right Label Sale Status:     ComboBox   cbxSaleStatus Items: Available Sold Processing Other Button Reset btnReset   Button Submit Changes btnSubmitChanges   Button Delete this Item btnDeleteStoreItem   Button Close btnClose

20. Double-click the Reset button
21. Implement the event as follows:

    private void btnReset_Click(object sender, EventArgs e)
    {
        txtItemNumber.Text = "";
        txtManufacturer.Text = "";
        cbxCategories.Text = "Women";
        txtItemName.Text = "";
        txtItemSize.Text = "";
        txtUnitPrice.Text = "0.00";
        txtManufacturer.Focus();
    }

22. Return to the form
23. Double-click the Find button
24. Implement its event as follows:

    private void btnFind_Click(object sender, EventArgs e)
    {
        double unitPrice = 0.00;
    
        if (txtItemNumber.Text == "")
        {
            return;
        }
    
        try
        {
            DataRow rcdStoreItem = 
    		taStoreItems.GetData().Rows.Find(txtItemNumber.Text);
    
            txtItemName.Text = rcdStoreItem["ItemName"].ToString();
            txtManufacturer.Text = rcdStoreItem["Manufacturer"].ToString();
            cbxCategories.Text = rcdStoreItem["Category"].ToString();
            cbxSubCategories.Text = rcdStoreItem["SubCategory"].ToString();
            txtItemName.Text = rcdStoreItem["itemName"].ToString();
            txtItemSize.Text = rcdStoreItem["ItemSize"].ToString();
            unitPrice = double.Parse(rcdStoreItem["UnitPrice"].ToString());
            txtUnitPrice.Text = unitPrice.ToString("F");
            cbxSaleStatus.Text = rcdStoreItem["SaleStatus"].ToString();
        }
        catch (NullReferenceException)
        {
            MessageBox.Show("There is no store item with that number",
                            "Fun Department Store",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
            btnReset_Click(sender, e);
    
        }
        catch (IndexOutOfRangeException)
        {
            MessageBox.Show("There is no store item with that number",
                            "Fun Department Store",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
            btnReset_Click(sender, e);
        }
    }

25. Display the Central form
26. Double-click the Manage Store Item
27. Implement the event as follows:

    private void btnManageStoreItem_Click(object sender, EventArgs e)
    {
        ManageStoreItem msi = new ManageStoreItem();
        msi.ShowDialog();
    }

28. Press Ctrl + F5 to execute
29. Display the Manage Store Item form
30. In the Item # text box, typer 557504
31. Click Find
     
    
32. Enter 294725
33. Click Find
     
    
34. Close the forms and return to your programming environment

One of the most fundamental operations you can perform on a table adapter consists of creating a new record. To assist you with this, the table adapter class that the wizard generates is equipped with a method named Insert. This method takes one or more arguments depending on its table. This means that it takes an argument for each column of its table. To create a record for the table, call this method and pass the value of the columns observing the following rules:

You must pass a value for each column You can specify a value only for a column that exists on the table You must pass the values in the order they appear in the table If you don't have a value for a column, pass it as null You must pass a value in the appropriate type: int, string, decimal, etc. Because this is a C# class, the values must be passed in C# types Don't assign a value to a column whose records must be automatically specified. This is the case for a primary key column with an identity property Don't assign a value to a column whose records are specified by an expression Observe all check constraints If a column has a UNIQUE characteristic, you must not give it a value that exists already in the table

Here is an example:

private void btnAddNewRecord_Click(object sender, EventArgs e)
{
     taCustomers.Insert("204080", "Arsene Forland",
                        "(022) 197-0095", "Clint",
			"(048) 927-1153");
}

Editing a record consists of changing one or more of its values. To programmatically do this, you must first locate and open the record. Then change the necessary value(s). After doing this, if you want to apply the change to the table, you must update it. To assist you with this, the generated table adapter is equipped with the Update() method. This method is overloaded with four versions: one for a data set, one for a data table, one for a record (a data row), and one for an array of records (a DataRow[] array). Therefore, after making the changes on either a record, some records, or a table, call the appropriate version of the method to apply the changes. Here is an example:

private void btnUpdate_Click(object sender, EventArgs e)
{
    DataRow customer = taCustomers.GetData().Rows.Find("204080");

    customer["EmergencyName"] = "Alexander";
    customer["EmergencyPhone"] = "Balm";

    taCustomers.Update(customer);
}

1. Display the Shopping Session form
2. Double-click the Submit Current Order button
3. Implement its event as follows:

   private void btnSubmitOrder_Click(object sender, EventArgs e)
   {
       if (lvwShoppingSession.Items.Count == 0)
       {
           MessageBox.Show("There is no record to create.");
           return;
       }
   
       // Add the list of items to the CustomersOrders table
       try
       {
           for (int i = 0; i < lvwShoppingSession.Items.Count; i++)
           {
               taCustomersOrders.Insert(receiptNumber.ToString(),
                                        lblDate.Text,
                                        lblTime.Text,
                                        lvwShoppingSession.Items[i].Text,
                                    lvwShoppingSession.Items[i].SubItems[1].Text,
                      lvwShoppingSession.Items[i].SubItems[2].Text,
                      decimal.Parse(lvwShoppingSession.Items[i].SubItems[3].Text));
           
               DataRow rcdStoreItem = 
   	taStoreItems.GetData().Rows.Find(lvwShoppingSession.Items[i].Text);
               rcdStoreItem["SaleStatus"] = "Sold";
               taStoreItems.Update(rcdStoreItem);
           }
               
           // Let the user know
   	MessageBox.Show("The customer order has been saved.",
                           "Fun Department Store",
                           MessageBoxButtons.OK, MessageBoxIcon.Information);
   
       }
       catch (IndexOutOfRangeException)
       {
           MessageBox.Show("There is no store item with that number",
                           "Fun Department Store",
                           MessageBoxButtons.OK, MessageBoxIcon.Information);
       }
   
       // Create a record in the ReceiptSummaries table
       try
       {
           taReceiptsSummaries.Insert(receiptNumber.ToString(),
                                      lblDate.Text,
                                      lblTime.Text,
                                      decimal.Parse(txtOrderTotal.Text),
                                      cbxCurrencyType.Text,
                                      decimal.Parse(txtAmountTended.Text),
                                      decimal.Parse(txtChange.Text));
   
   	// Receipt the form
           btnCancelOrder_Click(sender, e);
       }
       catch (IndexOutOfRangeException)
       {
           MessageBox.Show("There is no store item with that number",
                           "Fun Department Store",
                           MessageBoxButtons.OK, MessageBoxIcon.Information);
       }
   }

4. Press Ctrl + F5 to execute the application
5. Click Process a Customer Order
6. Create a customer order that uses
    

   Item #:

   952735

7. Change the Amount Tended to 500 and press Tab
8. Click Submit Current Order
9. Create another customer order that uses
    

   Item #:	927940
   Item #:	790064

10. Change the Amount Tended to 300 and press Tab
11. Click Submit Current Order
12. Create another customer order that uses
     

    Item #:	290030
    Item #:	790402
    Item #:	729741
    Item #:	297030

13. Change the Amount Tended to 300 and press Tab
14. Click Submit Current Order
15. Create another customer order that uses
     

    Item #:

    797140

16. Change the Amount Tended to 20 and press Tab
17. Click Submit Current Order
18. Close the forms and return to your programming environment
19. Display the Manage Store Item form
20. Double-click the Submit Changes button
21. Implement its Click event as follows:

    private void btnSubmitChanges_Click(object sender, EventArgs e)
    {
        if (txtItemNumber.Text.Length == 0)
        {
            MessageBox.Show("You must provide a (unique) item number.",
                            "Fun Department Store",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
    
        if (txtItemName.Text.Length == 0)
        {
            MessageBox.Show("You must provide a name for the item.",
                            "Fun Department Store",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
    
        if (txtUnitPrice.Text.Length == 0)
        {
            MessageBox.Show("You must provide a price for the item.",
                            "Fun Department Store",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
    
        try
        {
            DataRow rcdStoreItem = 
            	taStoreItems.GetData().Rows.Find(txtItemNumber.Text);
    
            if (txtManufacturer.Text.Length != 0)
                        rcdStoreItem["Manufacturer"] = txtManufacturer.Text;
            if (cbxCategories.Text.Length != 0)
                        rcdStoreItem["Category"] = cbxCategories.Text;
            if (cbxSubCategories.Text.Length != 0)
                        rcdStoreItem["SubCategory"] = cbxSubCategories.Text;
            rcdStoreItem["ItemName"] = txtItemName.Text;
            if (txtItemSize.Text.Length != 0)
                        rcdStoreItem["ItemSize"] = txtItemSize.Text;
            rcdStoreItem["UnitPrice"] = txtUnitPrice.Text.ToString();
    
            taStoreItems.Update(rcdStoreItem);
            
    	// Let the user know
            MessageBox.Show("The item has been updated",
                            "Fun Department Store",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
    
            btnReset_Click(sender, e);
       }
       catch (IndexOutOfRangeException)
       {
            MessageBox.Show("There is no store item with that number",
                            "Fun Department Store",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
       }
    }

22. Press Ctrl + F5 to execute the application
23. Click the Manage a Store Item button
24. Item the item number, enter 582604 and click Find
25. If the record is found, change the values as follows:
     

    	Manufacturer	Delete
    	Item Name	Sleeveless Sweater Dress
    	Size	L
    	Unit Price	125
    	Sale Status	Available

26. Click Submit Changes
27. In the item number, enter 770240 and click Find
28. If the record is found, change the values as follows:
     

    Manufacturer	Caparros
    Sub Category	Shoes
    Item Name	Peep-Toe Silk Stiletto Sandals
    Size	7.5
    Unit Price	65.00
    Sale Status	Available

29. Click Submit Changes
30. Close the forms and return to your programming environment