Home

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

   

Creating Table Adapters

 

Introduction

As its name indicates, a table adapter is an object that gives access to a database's table. As we have seen in previous lessons, to create a table adapter, you can use the Data Source Configuration Wizard.

 

Practical LearningPractical Learning: Introducing Data Sets

  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:
     
    Department Store
    Control Text Name
    Button Button Process a Customer Order btnProcessOrder
    Button Button Create a New Store Item btnCreateStoreItem
    Button Button View Current Store Inventory btnCurrentInventory
    Button Button Manage a Store Items btnManageStoreItem
    Button 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:
     
    Department Store
    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();
    }

A Class for a Table Adapter

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.

Shoe

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.

Practical LearningPractical Learning: Generating a Table Adapter

  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
     
    Data Source Configuration Wizard
  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

Getting the Records of a Table Adapter

Shirt

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();
}

Ceil Inn

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.

Practical LearningPractical Learning: Getting the Records

  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: 
    Department Store - Store Inventory
    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
Department Store - Store Inventory

Operations on a Table Adapter

   

Introduction

Jewelry

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.

Locating a Record Based on a Column

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.

Practical LearningPractical Learning: Locating a Record Based on a Column Name

  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);
    }

Locating a Record Using the DataRowCollection's Find

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:

Jewelry
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());
}

Practical LearningPractical Learning: Finding a Record

  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:
     
    Department Store
    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
     
    Department Store
  32. Enter 294725
  33. Click Find
     
    Department Store
  34. Close the forms and return to your programming environment

Creating a Record

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
Jacket

Here is an example:

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

Updating or Editing a Record

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);
}

Practical LearningPractical Learning: Adding and/or Updating a Record

  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:
     
    Dress Manufacturer Delete Dress
    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
 

Home Copyright © 2011 C#Key Next