Home

ADO.NET, C#, and the .NET Framework

   

ADO.NET and C#

 

Introduction

ADO.NET is primarily a concept of how to create visual databases. It is neither a technology nor a programming environment. You must use a computer language, such as C#, to make a graphical application connect to an actual database in a server, such as Microsoft SQL Server. This also means that you will follow the rules of your programming language to make your application work. Besides the language, you can also use one or more library to get whatever behavior you want and is possible. An example library is the .NET Framework.

Windows Controls

Since we have reviewed different controls and their options, there is no reason to go through that again. Still, you should be familiar with the strengths, weaknesses, and options of each control. You should make sure you apply the appropriate restrictions where necessary such as making sure that user can only select a date instead of typing one,

ADO.NET and Collection Classes

   

Introduction

As you may imagine, a database is primarily a list of values. As such, you can use a collection class in your database or even use a formal database in your collection-based application. To do this, you start by creating a connection to a database:

Connection

After establishing a connection to a database, you can use a command to specify the type of operation you want to perform, such as selecting records from a table, optionally using a condition. To get the data produced by the command, we saw that you could either use a data reader or a data adapter. If you use a data adapter, you can retrieve the values from the data adapter and store them in a data set:

Data Connection to a Data Set

This is where, once again, a data set object becomes (very) valuable. Remember that a data set object contains one or more tables. Once you can identify a table from a data set, you can create a class that shares its structure. Then use the data from that table and temporarily store it in a collection-based class:

Once the data is available in a collection class, you can manipulate it using a regular class you would have created. This allows you to use your knowledge of collections to explore a database.

Practical LearningPractical Learning: Introducing Databases and Collection Classes

  1. Start Microsoft Visual Studio
  2. To create a new application, on the main menu, click FILE -> New -> Project...
  3. Make sure Windows Forms Application. Set the Name to CollegeParkAutoParts2
  4. Click OK
  5. To create a new database, in the Server Explorer, right-click Data Connections and click Create New SQL Server Database...
  6. In the Server Name combo box, select your server or type (local)
  7. Set the database name as CollegeParkAutoParts1 and click OK
  8. In the Server Explorer, right-click the CollegeParkAutoParts1 connection and click New Query
  9. Open the CollegeParkAutoParts1 file and select everything in it the document
  10. Copy and paste it in the Query window
  11. Right-click inside the document and click Execute
  12. In the Solution Explorer, right-click Form1.cs and click Rename
  13. Type CollegeParkAutoParts.cs and press Enter
  14. On the message box that appears, click Yes
  15. To create a dialog box, on the main menu, click PROJECT -> Add Windows Form...
  16. Set the name to MakeEditor and click Add
  17. Design the form as follows:
     
    Make Editor
    Control Text Name Other Properties
    Label Label &Make:    
    TextBox Text Box   txtMake Modifiers: Public
    Button Button OK btnOK DialogResult: OK
    Button Button Cancel btnCancel DialogResult: Cancel
    Form Property Value
    FormBorderStyle FixedDialog
    Text Make Editor
    StartPosition CenterScreen
    AcceptButton btnOK
    CancelButton btnCancel
    MaximizeBox False
    MinimizeBox False
    ShowInTaskbar False
  18. To create a dialog box, on the main menu, click PROJECT -> Add Windows Form...
  19. Set the name to ModelEditor and click Add
  20. Design the form as follows:
     
    College Park Auto Parts: Model Editor
    Control Text Name Other Properties
    Label Label &Model:    
    TextBox Text Box   txtModel Modifiers: Public
    Button Button OK btnOK DialogResult: OK
    Button Button Cancel btnCancel DialogResult: Cancel
    Form Property Value
    FormBorderStyle FixedDialog
    Text Model Editor
    StartPosition CenterScreen
    AcceptButton btnOK
    CancelButton btnCancel
    MaximizeBox False
    MinimizeBox False
    ShowInTaskbar False
  21. To create a dialog box, in the Solution Explorer, right-click CollegeParkAutoParts3 -> Add -> Windows Form...
  22. Set the name to CategoryEditor and click Add
  23. Design the form as follows:
     
    College Park Auto Parts: Category Editor
    Control Text Name Other Properties
    Label Label &Category:    
    TextBox Text Box   txtCategory Modifiers: Public
    Button Button OK btnOK DialogResult: OK
    Button Button Cancel btnCancel DialogResult: Cancel
    Form Property Value
    FormBorderStyle FixedDialog
    Text Category Editor
    StartPosition CenterScreen
    AcceptButton btnOK
    CancelButton btnCancel
    MaximizeBox False
    MinimizeBox False
    ShowInTaskbar False
  24. On the main menu, click PROJECT -> Add Windows Form...
  25. Set the Name to PartEditor and click Add
  26. Design the form as follows:
     
    College Park Auto-Part - Part Editor
    Control Text Name Other Properties
    Label Label &Year:    
    ComboBox Combo Box   cbxYears  
    Label Label &Make:    
    ComboBox Combo Box   cbxMakes  
    Button Button New C&ategory... btnNewMake  
    Label Label M&odel:    
    ComboBox Combo Box   cbxModels  
    Button Button New Mo &del... btnNewModel  
    Label Label &Category:    
    ComboBox Combo Box   cbxCategories  
    Button Button New Ca&tegory btnNewCategory  
    Label Label &Part Name:    
    TextBox Text Box   txtPartName  
    Label Label &Unit Price:    
    TextBox Text Box 0.00 txtUnitPrice TextAlign: Right
    Label Label Part #:    
    TextBox Text Box   txtPartNumber Enabled: False
    Button Button Submit btnSubmit  
    Button Button Close btnClose DialogResult: Cancel
    Form Property Value
    FormBorderStyle FixedDialog
    Text College Park Auto -Parts: Part Editor
    StartPosition CenterScreen
    MaximizeBox False
    MinimizeBox False
    ShowInTaskbar False
  27. Double-click the New Make button and 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 CollegeParkAutoParts2
    {
        public partial class PartEditor : Form
        {
            public PartEditor()
            {
                InitializeComponent();
            }
    
            private void btnNewMake_Click(object sender, EventArgs e)
            {
                MakeEditor editor = new MakeEditor();
    
                if (editor.ShowDialog() == DialogResult.OK)
                {
                    if (editor.txtMake.Text.Length > 0)
                    {
                        string strMake = editor.txtMake.Text;
    
                        // Make sure the category is not yet in the list
                        if (cbxMakes.Items.Contains(strMake))
                        {
                            MessageBox.Show(strMake + " is already in the list.",
    	                                "College Park Auto-Parts",
            	                MessageBoxButtons.OK, MessageBoxIcon.Information);
            	    }
                        else
                        {
                            // Since this is a new category, add it to the combox box
                            cbxMakes.Items.Add(strMake);
                        }
    
                        cbxMakes.Text = strMake;
                    }
                }
            }        
        }
    }
  28. Return to the Part Editor form and double-click the New Model button
  29. Implement its event as follows:
    private void btnNewModel_Click(object sender, EventArgs e)
    {
        ModelEditor editor = new ModelEditor();
    
        if (editor.ShowDialog() == DialogResult.OK)
        {
            if (editor.txtModel.Text.Length > 0)
            {
                string strModel = editor.txtModel.Text;
    
                // Make sure the category is not yet in the list
                if (cbxModels.Items.Contains(strModel))
                {
                    MessageBox.Show(strModel + " is already in the list.",
    	                        "College Park Auto-Parts",
            	                MessageBoxButtons.OK, MessageBoxIcon.Information);
          	    }
                else
                {
                    // Since this is a new category, add it to the combox box
                    cbxModels.Items.Add(strModel);
                }
    
                cbxModels.Text = strModel;
            }
        }
    }
  30. Return to the Part Editor form and double-click the New Category button
  31. Implement its event as follows:
    private void btnNewCategory_Click(object sender, EventArgs e)
    {
        CategoryEditor editor = new CategoryEditor();
    
        if (editor.ShowDialog() == DialogResult.OK)
        {
            if (editor.txtCategory.Text.Length > 0)
            {
                string strCategory = editor.txtCategory.Text;
    
                // Make sure the category is not yet in the list
                if (cbxCategories.Items.Contains(strCategory))
                {
                    MessageBox.Show(strCategory + " is already in the list.",
    	                        "College Park Auto-Parts",
            	                MessageBoxButtons.OK, MessageBoxIcon.Information);
            	}
                else
                {
                    // Since this is a new category, add it to the combo box
                    cbxCategories.Items.Add(strCategory);
                }
    
                cbxCategories.Text = strCategory;
            }
        }
    }
  32. Return to the Part Editor form and double-click the Submit button
  33. Implement the event as follows:
    private void btnSubmit_Click(object sender, EventArgs e)
    {
        double UnitPrice = 0.00;
    
        if (cbxYears.Text == "")
        {
            MessageBox.Show("You must specify the year of the car.",
    	                "College Park Auto-Parts",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
    
        if (cbxMakes.Text == "")
        {
            MessageBox.Show("You must specify the car manufacturer.",
    	                "College Park Auto-Parts",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
    
        if (cbxModels.Text == "")
        {
            MessageBox.Show("You must specify the car model.",
    	                "College Park Auto-Parts",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
    
        if (txtPartName.Text == "")
        {
            MessageBox.Show("You must enter the name of the part.",
    	                "College Park Auto-Parts",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
    
        if (txtUnitPrice.Text == "")
        {
            MessageBox.Show("You must enter the unit price of the part.",
    	                "College Park Auto-Parts",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
    
        try
        {
            UnitPrice = double.Parse(txtUnitPrice.Text);
        }
        catch (FormatException)
        {
            MessageBox.Show("Invalid Unit Price.",
    	                "College Park Auto-Parts",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
    
        using (SqlConnection cnnNewPart =
               new SqlConnection("Data Source=(local);" +
                                 "Database=CollegeParkAutoParts1;" +
                                 "Integrated Security=SSPI;"))
        {
            SqlCommand cmdAutoPart =
            	new SqlCommand("INSERT INTO Inventory.AutoParts(" +
                                   "PartNumber, CarYear, Make, Model, Category, " +
                                   "PartName, UnitPrice) VALUES(" + txtPartNumber.Text + ", " +
                                   cbxYears.Text + ", N'" + cbxMakes.Text + "', N'" +
                                   cbxModels.Text + "', N'" + cbxCategories.Text + "', N'" +
                                   txtPartName.Text + "', " + double.Parse(txtUnitPrice.Text) + ");",
                                   cnnNewPart);
    
            cnnNewPart.Open();
            cmdAutoPart.ExecuteNonQuery();
    
            MessageBox.Show("The new part has been added.",
    	                "College Park Auto-Parts",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
    }
  34. Display the College Park Auto-Parts form (the main form)
  35. From the Components section of the Toolbox, click ImageList and click the form
  36. In the Properties window, click (Name) and type imgAutoParts
  37. Click the ellipsis button of the Images field
  38. In the Image Collection Editor, click Add
  39. Locate the folder that contains the resources for ated and display it in the Look In combo box
  40. Select the following icons: Sign1, Sign2, Cliper1, Cliper2, Rulers1, Rulers2, Graph1, Graph2, Tool1, and Tool2
  41. Click Open
     
    Image Collection Editor
  42. Click OK
  43. Design the form as follows:
     
    College Park Auto Parts - Form Design
    Control Text Name Other Properties
    Label Label College Park Auto-Parts   Font: Times New Roman, 20.25pt, style=Bold
    ForeColor: Blue
    Panel Panel     Height: 2
    GroupBox Group Box Part Identification    
    TreeView Tree View   tvwAutoParts ImageList: imgAutoParts
    GroupBox Group Box Available Parts    
    ListView List View   lvwAutoParts FullRowSelect: True
    GridLines: True
    View: Details
    Columns   (Name) Text TextAlign Width
    colPartNumber Part #    
    colPartName Part Name   300
    colUnitPrice Unit Price Right 80
    GroupBox Group Box Customer Order - Selected Parts    
    Label Label Part #    
    Label Label Part Name    
    Label Label Unit Price    
    Label Label Qty    
    Label Label Sub Total    
    TextBox Text Box   txtPartNumber  
    TextBox Text Box   txtPartName  
    TextBox Text Box 0.00 txtUnitPrice TextAlign: Right
    TextBox Text Box 0 txtQuantity TextAlign: Right
    TextBox Text Box 0.00 txtSubTotal TextAlign: Right
    Button Button Add/Select btnAdd
    ListView List View   lvwSelectedParts FullRowSelect: True
    GridLines: True
    View: Details
    Columns   (Name) Text TextAlign Width
    colPartNumberSelected Part #   45
    colPartNameSelected Part Name   274
    colUnitPriceSelected Unit Price Right 58
    colQuantitySelected Qty Right 28
    colSubTotalSelected Sub-Total Right 58
    GroupBox Group Box Order Summary    
    Button Button New Au&to Part... btnNewAutoPart  
    Label Label Receipt #:    
    TextBox Text Box txtSave  
    Button Button Save btnSave  
    Label Label Tax Rate:    
    TextBox Text Box 7.75 txtTaxRate TextAlign: Right
    Label Label %    
    Label Label Parts Total:    
    TextBox Text Box 0.00 txtPartsTotal TextAlign: Right
    Button Button &New Customer Order btnNewCustomerOrder  
    Label Label Receipt #:  
    TextBox Text Box   txtOpen
    Button Button Save btnOpen
    Label Label Tax Amount:
    TextBox Text Box 0.00 txtTaxAmount TextAlign: Right
    Label Label Order Total:
    TextBox Text Box 0.00 txtOrderTotal TextAlign: Right
    Button Button Close btnClose  
  44. Click the Available Parts list view
  45. In the Properties window, click the Events button and, in the Events section, double-click DoubleClick
  46. 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 CollegeParkAutoParts2
    {
        public partial class CollegeParkAutoParts : Form
        {
            public CollegeParkAutoParts()
            {
                InitializeComponent();
            }
    
            private void lvwAutoParts_DoubleClick(object sender, EventArgs e)
            {
                ListViewItem lviAutoPart = lvwAutoParts.SelectedItems[0];
    
                if ((lvwAutoParts.SelectedItems.Count == 0) ||
                    (lvwAutoParts.SelectedItems.Count > 1))
                    return;
    
                txtPartNumber.Text = lviAutoPart.Text;
                txtPartName.Text = lviAutoPart.SubItems[1].Text;
                txtUnitPrice.Text = lviAutoPart.SubItems[2].Text;
    
                txtQuantity.Text = "1";
                txtSubTotal.Text = lviAutoPart.SubItems[2].Text;
    
                txtQuantity.Focus();
            }
        }
    }
  47. Return to the College Park Auto-Parts form
  48. Click the Unit Price text box and, in the Events section of the Properties window, double-click Leave
  49. Implement the event as follows:
    private void txtUnitPrice_Leave(object sender, EventArgs e)
    {
        double UnitPrice = 0.00D;
        int Quantity = 0;
        double SubTotal = 0.00D;
    
        try
        {
            UnitPrice = double.Parse(txtUnitPrice.Text);
        }
        catch (FormatException)
        {
            MessageBox.Show("Invalid Unit Price!",
                            "College Park Auto-Parts",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
    
        try { Quantity = int.Parse(txtQuantity.Text); }
        catch (FormatException)
        {
            MessageBox.Show("Invalid Quandtity!",
                            "College Park Auto-Parts",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
    
        SubTotal = UnitPrice * Quantity;
        txtSubTotal.Text = SubTotal.ToString("F");
    }
    
    internal void CalculateOrder()
    {
        if (lvwSelectedParts.Items.Count == 0)
        {
            txtPartsTotal.Text = "0.00";
            txtTaxAmount.Text = "0.00";
            txtOrderTotal.Text = "0.00";
            return;
        }
    
        // Calculate the current total order and update the order
        double PartsTotal = 0.00;
        double TaxRate = 0.00;
        double TaxAmount = 0.00;
        double OrderTotal = 0.00;
    
        foreach (ListViewItem lvi in lvwSelectedParts.Items)
        {
            ListViewItem.ListViewSubItem SubItem = lvi.SubItems[4];
    
            PartsTotal += double.Parse(SubItem.Text);
        }
    
        try
        {
            TaxRate = double.Parse(txtTaxRate.Text) / 100;
        }
        catch (FormatException)
        {
            MessageBox.Show("Invalid Tax Rate",
                            "College Park Auto-Parts",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
    
        TaxAmount = PartsTotal * TaxRate;
        OrderTotal = PartsTotal + TaxAmount;
    
        txtPartsTotal.Text = PartsTotal.ToString("F");
        txtTaxAmount.Text = TaxAmount.ToString("F");
        txtOrderTotal.Text = OrderTotal.ToString("F");
    }
  50. Return to the College Park Auto-Parts form and click the Qty text box
  51. In the Events section of the Properties, click Leave, then click the arrow of its combo box and select txtUnitPrice_Leave
  52. On the College Park Auto-Parts form, click the Selected Part list view (the list view in the bottom-right section of the form)
  53. In the Events section of the Properties window, double-click DoubleClick
  54. Implement the event as follows:
    private void lvwSelectedParts_DoubleClick(object sender, EventArgs e)
    {
        ListViewItem lviSelectedPart = lvwSelectedParts.SelectedItems[0];
    
        if ((lvwSelectedParts.SelectedItems.Count == 0) ||
            (lvwSelectedParts.SelectedItems.Count > 1))
            return;
    
        txtPartNumber.Text = lviSelectedPart.Text;
        txtPartName.Text   = lviSelectedPart.SubItems[1].Text;
        txtUnitPrice.Text  = lviSelectedPart.SubItems[2].Text;
        txtQuantity.Text   = lviSelectedPart.SubItems[3].Text;
        txtSubTotal.Text   = lviSelectedPart.SubItems[4].Text;
    
        lvwSelectedParts.Items.Remove(lviSelectedPart);
        CalculateOrder();
    }
 
 
 

Using a Collection-Based Class

As reviewed above, before using a regular class to manipulate a database, you should first create a class. To do this, you must know the structure of the table that will be represented by the class. This means that you should be familiar with the tables in the data set object. After creating the class, to get the values from a table, you can declare a variable from a collection-based class. Then, you can use the properties and methods of the collection class.

Practical LearningPractical Learning: Using a Collection-Based Class

  1. In the Solution Explorer, right-click CollegeParkAutoParts2 -> Add -> Class...
  2. Set the name to AutoPart and press Enter
  3. Create a class as follows:
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    
    namespace CollegeParkAutoParts2
    {
        public class AutoPart
        {
            public int PartNumber   { get; set; }
    	public int CarYear      { get; set; }
    	public string Make      { get; set; }
    	public string Model     { get; set; }
    	public string Category  { get; set; }
    	public string PartName  { get; set; }
    	public double UnitPrice { get; set; }
        }
    }
  4. Display the Part Editor form and double-click an empty area of its body
  5. Implement the event as follows:
    internal void ResetPartEditor()
    {
        cbxYears.Items.Clear();
        cbxMakes.Items.Clear();
        cbxModels.Items.Clear();
        cbxCategories.Items.Clear();
        cbxYears.Text = "";
        cbxMakes.Text = "";
        cbxModels.Text = "";
        cbxCategories.Text = "";
        txtPartName.Text = "";
        txtUnitPrice.Text = "0.00";
    
        Random rndNumber = new Random();
    
        txtPartNumber.Text = rndNumber.Next(100001, 999999).ToString();
    
        // Put the years in the top combo box
        // Start with next year down to 1960
        for (int i = DateTime.Today.Year + 1; i >= 1960; i--)
            cbxYears.Items.Add(i.ToString());
     
        // Prepare a data set object for the parts
        DataSet dsParts = new DataSet("PartsSet");
    
        // Establish a connection to the database
        using (SqlConnection scCollegeParkAutoParts =
            new SqlConnection("Data Source=(local);" +
                              "Database=CollegeParkAutoParts1;" +
                              "Integrated Security=SSPI;"))
        {
            // Create a command that will select the parts
            SqlCommand cmdParts =
                new SqlCommand("SELECT PartNumber, " +
                               "       CarYear, " +
                               "       Make, " +
                               "       Model, " +
                               "       Category, " +
                               "       PartName, " +
                               "       UnitPrice " +
                               "FROM Inventory.AutoParts;", scCollegeParkAutoParts);
            cmdParts.CommandType = CommandType.Text;
            // Open the connection
            scCollegeParkAutoParts.Open();
    
            // Create a data adapter that will get the values from the table
            SqlDataAdapter sdaParts = new SqlDataAdapter(cmdParts);
            // Store those values in the data set
            sdaParts.Fill(dsParts);
    
            // Create an auto part object
            AutoPart StoreItem = null;
            // Create an empty list of auto parts
            List<AutoPart> lstAutoParts = new List<AutoPart>();
    
            // Check each record from the (only) table in the data set
            foreach (DataRow row in dsParts.Tables[0].Rows)
            {
                // Use the auto part object ...
                StoreItem = new AutoPart();
                // ... to create a record object
                StoreItem.PartNumber = int.Parse(row[0].ToString());
                StoreItem.CarYear = int.Parse(row[1].ToString());
                StoreItem.Make = row[2].ToString();
                StoreItem.Model = row[3].ToString();
                StoreItem.Category = row[4].ToString();
                StoreItem.PartName = row[5].ToString();
                StoreItem.UnitPrice = double.Parse(row[6].ToString());
                // Once the record is ready, store it in the collection variable
                lstAutoParts.Add(StoreItem);
            }
    
            // To avoid duplicate values in the combo boxes, 
            // we will use collection classes
            List<string> lstMakes = new List<string>();
            List<string> lstCategories = new List<string>();
    
            // Check the list of makes
            foreach (AutoPart part in lstAutoParts)
            {
                // If the list doesn't yet contain the make, add it
                if (!lstMakes.Contains(part.Make))
                    lstMakes.Add(part.Make);
            }
    
            // Once we have the list of makes, 
            // put them in the Make combo box
            foreach (string strMake in lstMakes)
                cbxMakes.Items.Add(strMake);
    
            foreach (AutoPart part in lstAutoParts)
            {
                if (!lstCategories.Contains(part.Category))
                    lstCategories.Add(part.Category);
            }
    
            foreach (string strCategory in lstCategories)
                cbxCategories.Items.Add(strCategory);
        }
    }
    
    private void PartEditor_Load(object sender, EventArgs e)
    {
        ResetPartEditor();
    }
  6. Call the ResetPartEditor() method before the closing curly bracket of the Click event of the Submit button:
    private void btnSubmit_Click(object sender, EventArgs e)
    {
        . . . No Change            
                 
        ResetPartEditor();
    }
  7. Return to the Part Editor form and double-click the Year combo box
  8. Implement the event as follows:
    private void cbxYears_SelectedIndexChanged(object sender, EventArgs e)
    {
        // If the user was working on a previous part, cancel it
        cbxModels.Items.Clear();
    }
  9. Return to the Part Editor form and double-click the Make combo box
  10. Implement its event as follows:
    private void cbxMakes_SelectedIndexChanged(object sender, EventArgs e)
    {
        // Create a data set of parts
        DataSet dsParts = new DataSet("PartsSet");
    
        // Establish a connection to the database
        using (SqlConnection scCollegeParkAutoParts =
            new SqlConnection("Data Source=(local);" +
                              "Database=CollegeParkAutoParts1;" +
                              "Integrated Security=SSPI;"))
        {
            // Create a command that will select the parts
            SqlCommand cmdParts =
            new SqlCommand("SELECT PartNumber, " +
                           "       CarYear, " +
                           "       Make, " +
                           "       Model, " +
                           "       Category, " +
                           "       PartName, " +
                           "       UnitPrice " +
                           "FROM Inventory.AutoParts;", scCollegeParkAutoParts);
            // Open the connection
            scCollegeParkAutoParts.Open();
    
            // Create a data adapter that will get 
            // the record from the command
            SqlDataAdapter sdaParts = new SqlDataAdapter(cmdParts);
    
            // Store those records in the data set
            sdaParts.Fill(dsParts);
    
            // Create an empty object that can receive one record
            AutoPart StoreItem = null;
            // Create an empty list that can receive a list of records
            List<AutoPart> lstAutoParts = new List<AutoPart>();
    
            // Check each record
            foreach (DataRow row in dsParts.Tables[0].Rows)
            {
                // Get the values of the current record
                StoreItem = new AutoPart();
                // Store the values in the object
                StoreItem.PartNumber = int.Parse(row[0].ToString());
                StoreItem.CarYear = int.Parse(row[1].ToString());
                StoreItem.Make = row[2].ToString();
                StoreItem.Model = row[3].ToString();
                StoreItem.Category = row[4].ToString();
                StoreItem.PartName = row[5].ToString();
                StoreItem.UnitPrice = double.Parse(row[6].ToString());
                // Once the record is ready, store it in the collection
                lstAutoParts.Add(StoreItem);
            }
    
            // This will hold the list of parts
            List<string> lstModels = new List<string>();
    
            foreach (AutoPart part in lstAutoParts)
            {
                if ((part.CarYear == int.Parse(cbxYears.Text)) &&
                    (part.Make == cbxMakes.Text))
                {
                    if (!lstModels.Contains(part.Model))
                        lstModels.Add(part.Model);
                }
            }
    
            foreach (string strModel in lstModels)
                cbxModels.Items.Add(strModel);
        }
    }
  11. Access the College Park Auto-Parts form and double-click anunoccupied area of its body
  12. Implement the event as follows:
    internal void ShowAutoParts()
    {
        tvwAutoParts.Nodes.Clear();
        TreeNode nodRoot =
        tvwAutoParts.Nodes.Add("College Park Auto-Parts",
                               "College Park Auto-Parts", 0, 1);
        // Show the years nodes
        for (int years = DateTime.Today.Year + 1; years >= 1960; years--)
            nodRoot.Nodes.Add(years.ToString(), years.ToString(), 2, 3);
    
        tvwAutoParts.SelectedNode = nodRoot;
        // Expand the root node
        tvwAutoParts.ExpandAll();
    
        // Create an empty data set
        DataSet dsParts = new DataSet("PartsSet");
    
        // Create a connection to the database
        using (SqlConnection scCollegeParkAutoParts =
            new SqlConnection("Data Source=(local);" +
                              "Database=CollegeParkAutoParts1;" +
                              "Integrated Security=SSPI;"))
        {
            // Use a command to specify what action we want to take
            SqlCommand cmdParts =
            new SqlCommand("SELECT PartNumber, " +
                           "       CarYear, " +
                           "       Make, " +
                           "       Model, " +
                           "       Category, " +
                           "       PartName, " +
                           "       UnitPrice " +
                           "FROM Inventory.AutoParts;", scCollegeParkAutoParts);
            // Open the connection
            scCollegeParkAutoParts.Open();
    
            // Use a data adapter to retrieve the values from the command
            SqlDataAdapter sdaParts = new SqlDataAdapter(cmdParts);
            // Fill the data set with the values from the data adapater
            sdaParts.Fill(dsParts);
    
            // Prepare a variable from the class we will use
            AutoPart StoreItem = null;
            // Create a collection
            List<AutoPart> lstAutoParts = new List<AutoPart>();
    
            // Check each record from the table from the data set
            foreach (DataRow row in dsParts.Tables[0].Rows)
            {
                // Identify each record as a value of our class
                StoreItem = new AutoPart();
                // Get the values of the record and put them in the class
                StoreItem.PartNumber = int.Parse(row[0].ToString());
                StoreItem.CarYear = int.Parse(row[1].ToString());
                StoreItem.Make = row[2].ToString();
                StoreItem.Model = row[3].ToString();
                StoreItem.Category = row[4].ToString();
                StoreItem.PartName = row[5].ToString();
                StoreItem.UnitPrice = double.Parse(row[6].ToString());
                // Store the record in the collection
                lstAutoParts.Add(StoreItem);
            }
    
            // Now that we have the records, 
            // we can use them as a normal collection
            foreach (TreeNode nodYear in nodRoot.Nodes)
            {
                List<string> lstMakes = new List<string>();
    
                foreach (AutoPart part in lstAutoParts)
                {
                    if (nodYear.Text == part.CarYear.ToString())
                    {
                        if (!lstMakes.Contains(part.Make))
                            lstMakes.Add(part.Make);
                    }
                }
    
                foreach (string strMake in lstMakes)
                    nodYear.Nodes.Add(strMake, strMake, 4, 5);
            }
    
            foreach (TreeNode nodYear in nodRoot.Nodes)
            {
                foreach (TreeNode nodMake in nodYear.Nodes)
                {
                    List<string> lstModels = new List<string>();
    
                    foreach (AutoPart part in lstAutoParts)
                    {
                        if ((nodYear.Text == part.CarYear.ToString()) &&
                            (nodMake.Text == part.Make))
                        {
                            if (!lstModels.Contains(part.Model))
                                lstModels.Add(part.Model);
                        }
                    }
    
                    foreach (string strModel in lstModels)
                        nodMake.Nodes.Add(strModel, strModel, 6, 7);
                }
            }
    
            foreach (TreeNode nodYear in nodRoot.Nodes)
            {
                foreach (TreeNode nodMake in nodYear.Nodes)
                {
                    foreach (TreeNode nodModel in nodMake.Nodes)
                    {
                        List<string> lstCategories = new List<string>();
    
                        foreach (AutoPart part in lstAutoParts)
                        {
                            if ((nodYear.Text == part.CarYear.ToString()) &&
                                (nodMake.Text == part.Make) &&
                                (nodModel.Text == part.Model))
                            {
                                if (!lstCategories.Contains(part.Category))
                                    lstCategories.Add(part.Category);
                            }
                        }
    
                        foreach (string strCategory in lstCategories)
                            nodModel.Nodes.Add(strCategory, strCategory, 8, 9);
                    }
                }
            }
        }
    }
    
    private void CollegeParkAutoParts_Load(object sender, EventArgs e)
    {
        ShowAutoParts();
    }	
    
  13. Return to the College Park Auto-Parts form and double-click the New Auto Part button
  14. Implement the event as follows:
    private void btnNewAutoPart_Click(object sender, EventArgs e)
    {
        PartEditor editor = new PartEditor();
    
        if (editor.ShowDialog() == DialogResult.Cancel)
            ShowAutoParts();
    }
  15. Return to the  College Park Auto-Parts form and click the tree view
  16. In the Properties window, click the Events button and, in the Events section, double-click NodeMouseClick
  17. Implement the event as follows:
    private void tvwAutoParts_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
    {
        TreeNode nodClicked = e.Node;
    
        if (nodClicked.Level == 4)
            lvwAutoParts.Items.Clear();
    
        DataSet dsParts = new DataSet("PartsSet");
    
        using (SqlConnection scCollegeParkAutoParts =
            new SqlConnection("Data Source=(local);" +
                              "Database=CollegeParkAutoParts1;" +
                              "Integrated Security=SSPI;"))
        {
            SqlCommand cmdParts =
            new SqlCommand("SELECT PartNumber, " +
                           "       CarYear, " +
                           "       Make, " +
                           "       Model, " +
                           "       Category, " +
                           "       PartName, " +
                           "       UnitPrice " +
                           "FROM Inventory.AutoParts;", scCollegeParkAutoParts);
            scCollegeParkAutoParts.Open();
    
            SqlDataAdapter sdaParts = new SqlDataAdapter(cmdParts);
            sdaParts.Fill(dsParts);
    
            AutoPart StoreItem = null;
            List<AutoPart> lstAutoParts = new List<AutoPart>();
    
            foreach (DataRow row in dsParts.Tables[0].Rows)
            {
                StoreItem = new AutoPart();
                StoreItem.PartNumber = int.Parse(row[0].ToString());
                StoreItem.CarYear = int.Parse(row[1].ToString());
                StoreItem.Make = row[2].ToString();
                StoreItem.Model = row[3].ToString();
                StoreItem.Category = row[4].ToString();
                StoreItem.PartName = row[5].ToString();
                StoreItem.UnitPrice = double.Parse(row[6].ToString());
                lstAutoParts.Add(StoreItem);
            }
    
            try
            {
                foreach (AutoPart part in lstAutoParts)
                {
                    if ((part.Category == nodClicked.Text) &&
                        (part.Model == nodClicked.Parent.Text) &&
                        (part.Make == nodClicked.Parent.Parent.Text) &&
                    (part.CarYear.ToString() == nodClicked.Parent.Parent.Parent.Text))
                    {
                        ListViewItem lviAutoPart =
                            new ListViewItem(part.PartNumber.ToString());
    
                        lviAutoPart.SubItems.Add(part.PartName);
                        lviAutoPart.SubItems.Add(part.UnitPrice.ToString("F"));
                        lvwAutoParts.Items.Add(lviAutoPart);
                    }
                }
            }
            catch (NullReferenceException)
            {
            }
        }
    }
  18. Return to the College Park Auto-Parts form and double-click the Add/Select button
  19. Implement the event as follows:
    private void btnAdd_Click(object sender, EventArgs e)
    {
        if (txtPartNumber.Text.Length == 0)
        {
            MessageBox.Show("There is no part to be added to the order.",
                            "College Park Auto-Parts",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
    
        DataSet dsParts = new DataSet("PartsSet");
    
        using (SqlConnection scCollegeParkAutoParts =
              new SqlConnection("Data Source=(local);" +
                                "Database=CollegeParkAutoParts1;" +
                                "Integrated Security=SSPI;"))
        {
            SqlCommand cmdParts =
         new SqlCommand("SELECT * FROM Inventory.AutoParts;", scCollegeParkAutoParts);
            scCollegeParkAutoParts.Open();
    
            SqlDataAdapter sdaParts = new SqlDataAdapter(cmdParts);
            sdaParts.Fill(dsParts);
    
            AutoPart StoreItem = null;
            List<AutoPart> lstAutoParts = new List<AutoPart>();
    
            foreach (DataRow row in dsParts.Tables[0].Rows)
            {
                StoreItem = new AutoPart();
                StoreItem.PartNumber = int.Parse(row[0].ToString());
                StoreItem.CarYear = int.Parse(row[1].ToString());
                StoreItem.Make = row[2].ToString();
                StoreItem.Model = row[3].ToString();
                StoreItem.Category = row[4].ToString();
                StoreItem.PartName = row[5].ToString();
                StoreItem.UnitPrice = double.Parse(row[6].ToString());
                lstAutoParts.Add(StoreItem);
            }
    
            foreach (AutoPart part in lstAutoParts)
            {
                if (part.PartNumber == int.Parse(txtPartNumber.Text))
                {
                    ListViewItem lviSelectedPart =
                        new ListViewItem(part.PartNumber.ToString());
    
                    lviSelectedPart.SubItems.Add(part.PartName);
                    lviSelectedPart.SubItems.Add(part.UnitPrice.ToString());
                    lviSelectedPart.SubItems.Add(txtQuantity.Text);
                    lviSelectedPart.SubItems.Add(txtSubTotal.Text);
                    lvwSelectedParts.Items.Add(lviSelectedPart);
                }
            }
    
            CalculateOrder();
        }
    }
  20. Return to the College Park Auto-Parts form and double-click the Save Customer Order button
  21. Implement the event as follows:
    private void btnSave_Click(object sender, EventArgs e)
    {
        if (lvwSelectedParts.Items.Count == 0)
            return;
        else
        {
            using (SqlConnection scAltairRealtors =
                new SqlConnection("Data Source=(local);" +
                           "Database='CollegeParkAutoParts1';" +
                           "Integrated Security='SSPI';"))
            {
                SqlCommand cmdProperty =
                    new SqlCommand("INSERT INTO Transactions.CustomersOrders(ReceiptNumber, " +
                                   "PartsTotal, TaxRate, TaxAmount, OrderTotal) VALUES(" + txtSave.Text + ", " +
                                   txtPartsTotal.Text + ", " + txtTaxRate.Text + ", " +
                                   txtTaxAmount.Text + ", " + txtOrderTotal.Text + ");",
                                   scAltairRealtors);
    
                scAltairRealtors.Open();
                cmdProperty.ExecuteNonQuery();
            }
    
            // Check each selected part and get it ready to add to the table
            // Each selected part of this order will have a common receipt #
            for (int i = 0; i < lvwSelectedParts.Items.Count; i++)
            {
                using (SqlConnection cnnCustomerOrder =
                  new SqlConnection("Data Source=(local);" +
                                    "Database=CollegeParkAutoParts1;" +
                                    "Integrated Security=SSPI;"))
                {
                    SqlCommand cmdCustomerOrder =
                        new SqlCommand("INSERT INTO Transactions.PartsSold(ReceiptNumber, PartNumber, PartName, " +
                        "UnitPrice, Quantity, SubTotal) VALUES(" + txtSave.Text + ", N'" +
                        lvwSelectedParts.Items[i].Text + "', '" +
                        lvwSelectedParts.Items[i].SubItems[1].Text + "', '" +
                        lvwSelectedParts.Items[i].SubItems[2].Text + "', '" +
                        lvwSelectedParts.Items[i].SubItems[3].Text + "', '" +
                        lvwSelectedParts.Items[i].SubItems[4].Text + "'); ", cnnCustomerOrder);
                    cnnCustomerOrder.Open();
    
                    cmdCustomerOrder.ExecuteNonQuery();
                }
            }
    
            MessageBox.Show("The customer order has been saved.",
                            "College Park Auto-Parts",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
    
        CollegeParkAutoParts_Load(sender, e);
    }
  22. Change the Load event as follows:
    private void SetReceiptNumber()
    {
        int iReceiptNumber = 0;
    
        using (SqlConnection scCustomersOrders =
           new SqlConnection(@"Data Source='CENTRAL\MSSQLSERVER2012';" +
                              "Database=CollegeParkAutoParts1;" +
                              "Integrated Security=SSPI;"))
        {
            SqlCommand cmdCustomersOrders =
                       new SqlCommand("SELECT ReceiptNumber " +
                             "FROM Transactions.CustomersOrders;", scCustomersOrders);
    
            scCustomersOrders.Open();
            SqlDataReader rdrCustomersOrders = cmdCustomersOrders.ExecuteReader();
    
            while (rdrCustomersOrders.Read())
                iReceiptNumber = int.Parse(rdrCustomersOrders[0].ToString());
        }
    
        txtSave.Text = (iReceiptNumber + 1).ToString();
    }
    
    private void CollegeParkAutoParts_Load(object sender, EventArgs e)
    {
        ShowAutoParts();
        SetReceiptNumber();
    
        lvwAutoParts.Items.Clear();
        txtPartNumber.Text = "";
        txtPartName.Text = "";
        txtUnitPrice.Text = "0.00";
        txtQuantity.Text = "0";
        txtSubTotal.Text = "0.00";
        lvwSelectedParts.Items.Clear();
        txtPartsTotal.Text = "0.00";
        txtTaxRate.Text = "5.75";
        txtTaxAmount.Text = "0.00";
        txtOrderTotal.Text = "0.00";
        txtOpen.Text = "";
    }
  23. Return to the College Park Auto-Parts form and double-click the Open button
  24. Implement the event as follows:
    private void btnOpen_Click(object sender, EventArgs e)
    {
        lvwSelectedParts.Items.Clear();
    
        if (string.IsNullOrEmpty(txtOpen.Text))
            return;
        else
        {
            using (SqlConnection cnnCustomerOrder =
                   new SqlConnection("Data Source=(local);" +
                                     "Database=CollegeParkAutoParts1;" +
                                     "Integrated Security=SSPI;"))
            {
                SqlCommand cmdCustomerOrder =
                    new SqlCommand("SELECT * FROM Transactions.PartsSold " +
                                   "WHERE ReceiptNumber = '" + txtOpen.Text + "';",
                                   cnnCustomerOrder);
                SqlDataAdapter sdaCustomerOrder =
                    new SqlDataAdapter(cmdCustomerOrder);
    
                cnnCustomerOrder.Open();
    
                DataSet dsCustomerOrder = new DataSet("PartsSoldSet");
                sdaCustomerOrder.Fill(dsCustomerOrder);
    
                for (int i = 0; i < dsCustomerOrder.Tables[0].Rows.Count; i++)
                {
                    DataRow rowOrder = dsCustomerOrder.Tables[0].Rows[i];
    
                    ListViewItem lviOrder =
                        new ListViewItem(rowOrder["PartNumber"].ToString());
                    lviOrder.SubItems.Add(rowOrder["PartName"].ToString());
                    lviOrder.SubItems.Add(rowOrder["UnitPrice"].ToString());
                    lviOrder.SubItems.Add(rowOrder["Quantity"].ToString());
                    lviOrder.SubItems.Add(rowOrder["SubTotal"].ToString());
                    lvwSelectedParts.Items.Add(lviOrder);
                }
            }
    
            using (SqlConnection cnnInvoice =
                   new SqlConnection("Data Source=(local);" +
                                     "Database=CollegeParkAutoParts1;" +
                                     "Integrated Security=SSPI;"))
            {
                string strInvoice = "SELECT ReceiptNumber, PartsTotal, TaxRate, " +
                                    "TaxAmount, OrderTotal " +
                                    "FROM Transactions.CustomersOrders " +
                                    "WHERE ReceiptNumber = " + txtOpen.Text + ";";
    
                SqlCommand cmdInvoice = new SqlCommand(strInvoice, cnnInvoice);
    
                cnnInvoice.Open();
                SqlDataReader rdrInvoice = cmdInvoice.ExecuteReader();
    
                while (rdrInvoice.Read())
                {
                    txtPartsTotal.Text = rdrInvoice[1].ToString();
                    txtTaxRate.Text = rdrInvoice[2].ToString();
                    txtTaxAmount.Text = rdrInvoice[3].ToString();
                    txtOrderTotal.Text = rdrInvoice[4].ToString();
                }
            }
        }
    }
  25. Return to the College Park Auto-Parts form and double-click the New Customer button
  26. Implement the event as follows:
    private void btnNewCustomerOrder_Click(object sender, EventArgs e)
    {
        ShowAutoParts();
        lvwAutoParts.Items.Clear();
        txtPartNumber.Text = "";
        txtPartName.Text = "";
        txtUnitPrice.Text = "0.00";
        txtQuantity.Text = "0";
        txtSubTotal.Text = "0.00";
        lvwSelectedParts.Items.Clear();
        txtPartsTotal.Text = "0.00";
        txtTaxRate.Text = "5.75";
        txtTaxAmount.Text = "0.00";
        txtOrderTotal.Text = "0.00";
        txtOpen.Text = "";
    }
  27. Return to the College Park Auto-Parts form and double-click the Close button
  28. Implement the event as follows:
    private void btnClose_Click(object sender, EventArgs e)
    {
        Close();
    }
  29. Execute the application
  30. Click the New Auto Part button and use the Part Editor to create a few parts
  31. Create a few customers orders and save them
  32. Close the forms and return to your programming environment
  33. Execute the application again and open a previously saved order
  34. Close the forms and return to your programming environment

Exercises

 

College Park Auto Parts

  1. Open the CollegeParkAutoParts3 database from this lesson
  2. Add a context menu for the Available Parts list view with the items: Select, Edit..., and Delete
     
  3. Configure the context menu so that
    1. If the user clicks Select, the behavior would be the same as if the user had double-clicked the item
    2. If the user clicks Edit..., the Part Editor dialog box would display with the part in it. The user can then edit any part (year, make, model, category, part name, or unit price) except the part number. Then the user can save the changed part
    3. If the user clicks Delete, a message box would warn the user and ask for confirmation with Yes/No answers. If the user clicks Yes, the part would be deleted from the AutoParts table
  4. Configure the application so that the user can open an order, add new parts to it, or delete parts from it, then save the order
  5. Extend the application so that the store can also sell items that are, or are not, car-related, such as books, t-shirts, cleaning items, maintenance items (steering oils, brake oils, etc), license plates, etc. Every item in the store should have an item number. The user can enter that item number in the Part # text box and press Tab or Enter. The corresponding item would then be retrieved from the database and displayed on the form. If there is no item with that number, a message box should let the user know
 
 
   
 

Home Copyright © 2003-2014, FunctionX