Consider the following table named Employees:

using System;
using System.Data;
using System.Drawing;
using System.Windows.Forms;
using System.Data.SqlClient;

public class Exercise : System.Windows.Forms.Form
{
    DataGridView dgvIdentifications;

    public Exercise()
    {
        InitializeComponent();
    }

    void InitializeComponent()
    {
        dgvIdentifications = new DataGridView();
        dgvIdentifications.Location = new Point(12, 12);
        dgvIdentifications.Size = new System.Drawing.Size(270, 250);

        Text = "Exercise";
        Controls.Add(dgvIdentifications);
        Load += new EventHandler(ExerciseLoad);

        dgvIdentifications.Anchor = AnchorStyles.Left | AnchorStyles.Top |
                                    AnchorStyles.Right | AnchorStyles.Bottom;
    }

    void ExerciseLoad(object sender, EventArgs e)
    {
        SqlConnectionStringBuilder csbExercise = new SqlConnectionStringBuilder();

        csbExercise.DataSource = "(local)";
        csbExercise.InitialCatalog = "Exercise1";
        csbExercise.IntegratedSecurity = true;

        using (SqlConnection cntExercise = new SqlConnection(csbExercise.ConnectionString))
        {
            SqlCommand cmdEmployees =
                new SqlCommand("CREATE SCHEMA Personnel;", cntExercise);
            cntExercise.Open();
            cmdEmployees.ExecuteNonQuery();
        }

        using (SqlConnection cntExercise =
            new SqlConnection("Data Source='(local)';" +
                              "Database='Exercise1';" +
                              "Integrated Security='SSPI';"))
        {
            SqlCommand cmdEmployees =
                new SqlCommand("CREATE TABLE Personnel.Employees(" +
                               "EmployeeNumber nchar(6) not null primary key, " +
                               "FirstName nvarchar(20), MiddleName nvarchar(20), " +
                               "LastName nvarchar(20), " +
                               "HourlySalary smallmoney, Status nvarchar(40));" +
                               "INSERT INTO Personnel.Employees " +
                               "VALUES(N'862804', N'Christopher', NULL, N'Larsen', 14.50, N'Full Time'), " +
                               "      (N'293747', N'Henry', N'Donald', N'Jonathan', 12.85, N'Full Time'), " +
                               "      (N'847597', N'Chistine', NULL, N'Garrison', 24.05, N'Part Time'), " +
                               "      (N'979558', N'Peter', NULL, N'Horries', NULL, NULL), " +
                               "      (N'385807', N'Lance', N'James', N'Seagal', 16.95, N'Full Time'), " +
                               "      (N'927405', N'Paula', N'Roberta', N'Ortez', NULL, N'Full Time'), " +
                               "      (N'790875', N'Paul', NULL, N'Swanson', 10.90, NULL), " +
                               "      (N'384096', N'Kristopher', N'Jude', N'Michaels', 12.85, N'Part Time'), " +
                               "      (N'385968', N'Jennifer', NULL, N'Sanders', 15.00, N'Part Time'), " +
                               "      (N'380696', N'David', N'Peter', N'Monahan', 13.05, N'Full Time');",
                               cntExercise);
            cntExercise.Open();
            cmdEmployees.ExecuteNonQuery();

            MessageBox.Show("A table named \"Employees\" has been created in the Personnel schema.",
                            "Exercise",
                            MessageBoxButtons.OK,
                            MessageBoxIcon.Information);
        }

        using (SqlConnection cntExercise = new SqlConnection(csbExercise.ConnectionString))
        {
            SqlCommand cmdEmployees = new SqlCommand(
                    "SELECT ALL * FROM Personnel.Employees;",
                    cntExercise);

            cntExercise.Open();
            cmdEmployees.ExecuteNonQuery();

            SqlDataAdapter sdaEmployees = new SqlDataAdapter(cmdEmployees);
            DataSet dsEmployees = new DataSet("EmployeesSet");

            sdaEmployees.Fill(dsEmployees);
            dgvIdentifications.DataSource = dsEmployees.Tables[0];
        }
    }

    public static int Main()
    {
        System.Windows.Forms.Application.Run(new Exercise());
        return 0;
    }
}

1. Start Microsoft Visual Studio
2. To start a new applicaiton, on the main menu, click FILE -> New Project...
3. In the middle list, click Windows Forms Application and set the Name to AltairRealtors1
4. Click OK
5. In the Solution Explorer, right-click Form1.cs and click Rename
6. Type AltairRealtors.cs and press Enter
7. Double-click the middle of the form and change the file 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.Threading.Tasks;
   using System.Windows.Forms;
   using System.IO;
   using System.Data.SqlClient;
   
   namespace AltairRealtors1
   {
       public partial class AltairRealtors : Form
       {
           public AltairRealtors()
           {
               InitializeComponent();
           }
   
           internal void CreateDatabase()
           {
               SqlConnection scAltairRealtors = null;
               SqlCommand cmdAltairRealtors = null;
   
               using (scAltairRealtors =
                   new SqlConnection("Data Source=(local);" +
                                      "Integrated Security='SSPI';"))
               {
                   cmdAltairRealtors =
                       new SqlCommand("IF EXISTS (" +
                                      "SELECT name " +
                                      "FROM sys.databases " +
                                      "WHERE name = N'AltairRealtors1')" +
                                      "DROP DATABASE AltairRealtors1; " +
                                      "CREATE DATABASE AltairRealtors1;", scAltairRealtors);
                   scAltairRealtors.Open();
                   cmdAltairRealtors.ExecuteNonQuery();
   
                   MessageBox.Show("The AltairRealtors1 database has been created.",
                                   "Altair Realtors",
                                   MessageBoxButtons.OK, MessageBoxIcon.Information);
               }
   
               using (scAltairRealtors =
                   new SqlConnection("Data Source=(local);" +
                                      "Database='AltairRealtors1';" +
                                      "Integrated Security='SSPI';"))
               {
                   cmdAltairRealtors =
                       new SqlCommand("CREATE SCHEMA Listings;", scAltairRealtors);
                   scAltairRealtors.Open();
                   cmdAltairRealtors.ExecuteNonQuery();
   
                   MessageBox.Show("A new schema named Listings has been created.",
                                   "Altair Realtors",
                                   MessageBoxButtons.OK, MessageBoxIcon.Information);
               }
   
               using (scAltairRealtors =
                   new SqlConnection("Data Source=(local);" +
                                      "Database='AltairRealtors1';" +
                                      "Integrated Security='SSPI';"))
               {
                   cmdAltairRealtors = new SqlCommand(
                       "CREATE TABLE Listings.Properties(" +
                       "PropertyID int identity(1, 1), PropertyNumber nvarchar(10) not null, PropertyType nvarchar(40), " +
                       "[Address] nvarchar(100), City nvarchar(50), [State] nchar(2), " +
                       "ZIPCode nvarchar(12), Bedrooms smallint, Bathrooms float, " +
                       "Stories smallint, FinishedBasement bit, IndoorGarage bit, " +
                       "YearBuilt smallint, Condition nvarchar(40), " +
                       "MarketValue money, SaleStatus nvarchar(50), " +
                       "Constraint PK_Properties Primary Key(PropertyNumber));",
                       scAltairRealtors);
                   scAltairRealtors.Open();
                   cmdAltairRealtors.ExecuteNonQuery();
   	    }
   
               MessageBox.Show("The Properties table has been created.",
                               "Altair Realtors",
                               MessageBoxButtons.OK, MessageBoxIcon.Information); 
   	}
   	
           private void AltairRealtors_Load(object sender, EventArgs e)
           {
               CreateDatabase();
           }
       }
   }

8. Press Ctrl + F5 to execute
9. Click OK on each message box
10. Close the form and return to your programming environment
11. To create a dialog box, on the main menu, click PROJECT -> Add Windows Form...
12. Set the name to NewRealEstateProperty and click Add
13. In the Dialogs section of the Toolbox, click OpenFileDialog
14. Click the form
15. In the Properties window, change its characteristics as follows:
    (Name):       dlgPicture
    DefaultExt:  jpg
    Filter:          JPEG Files (*.jpg,*.jpeg)|*.jpg
    Title:           Select House Picture
16. Design the form as follows:
     

    Control (Name) DropDownStyle Text Items Modifiers Other Properties Label     Property #:       TextBox txtPropertyNumber       Public   Label     Property Type:       ComboBox cbxPropertiesTypes DropDownList   Unknown Townhouse Condominium Single Family Public   Label     Address:       TextBox txtAddress       Public   Label     City:       TextBox txtCity       Public   Label     State/Province:       ComboBox cbxStates DropDownList   AB, AL, AK, AZ, AR, BC, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, MD, MA, MI, MN, MS, MO, MT, NB, NE, NV, NH, NJ, NL, NM, NS, NY, NC, ND, OH, OK, ON, OR, PA, PE, QC, RI, SC, SD, SK, TN, TX, UT, VT, VA, WA, WV, WI, WY Public   Label     ZIP/Postal Code:       TextBox txtZIPCode       Public   Label     Stories:       TextBox txtStories       Public   Label     Bedrooms:       TextBox txtBedrooms   0   Public   Label     Bathrooms:       TextBox txtBathrooms   0.00   Public   CheckBox chkFinishedBasement   Finished Basement       CheckBox chkIndoorGarage   Indoor Garage       Label     Year Built:       TextBox txtYearBuilt       Public   Label     Condition:       ComboBox cbxConditions DropDownList    Unknown Excellent Good Shape Needs Fixing Public   Label     Market Value:       TextBox txtMarketValue   0.00   Public   Label     Sale Status:       ComboBox cbxSalesStatus DropDownList   Unknown Available Sold Public   Button btnPicture   Picture...       PictureBox pbxProperty         BorderStyle: FixedSingle SizeMode: Zoom Button btnOK   OK     DialogResult: OK Button btnCancel   Cancel     DialogResult: Cancel
    Form
    FormBorderStyle:	FixedDialog
    Text:	Altair Realtors - New Real Estate Property
    StartPosition:	CenterScreen
    AcceptButton:	btnOK
    CancelButton:	btnCancel
    MaximizeBox:	False
    MinimizeBox:	False
    ShowInTaskBar:	False

17. Double-click an unoccupied area of the dialog box
18. Return to the form and double-click the Picture button
19. Change the document 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.Threading.Tasks;
    using System.Windows.Forms;
    using System.IO;
    
    namespace AltairRealtors1
    {
        public partial class NewRealEstateProperty : Form
        {
            public bool bPictureChanged;
            public string strPictureFile;
    
            public RealEstateProperty()
            {
                InitializeComponent();
            }
    
            private void NewRealEstateProperty_Load(object sender, EventArgs e)
            {
                bPictureChanged = false;
                Directory.CreateDirectory("C:\\Altair Realtors");
                strPictureFile = "C:\\Altair Realtors\\default.jpg";
            }
    
            private void btnPicture_Click(object sender, EventArgs e)
            {
                if (dlgPicture.ShowDialog() == DialogResult.OK)
                {
                    pbxProperty.Image = Image.FromFile(dlgPicture.FileName);
                    strPictureFile = dlgPicture.FileName;
                    bPictureChanged = true;
                }
            }
        }
    }

20. To create another dialog box, on the main menu, click PROJECT -> Add Windows Form...
21. Set the name to PropertyEditor and click Add
22. Change the size of the form to be the same size as the New Real Estate Property form
23. Add a button to the form and change its design as follows:
     

    Control (Name) Text TextAlign Button btnFind Find

24. Double-click the Picture button
25. Return to the form and double-click the Find button
26. Change the file 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.Threading.Tasks;
    using System.Windows.Forms;
    using System.IO;
    using System.IO;
    using System.Data.SqlClient;
    
    namespace AltairRealtors1
    {
        public partial class PropertyEditor : Form
        {
            public bool bPictureChanged;
            public string strPictureFile;
    
            public PropertyEditor()
            {
                InitializeComponent();
            }
    
            private void btnPicture_Click(object sender, EventArgs e)
            {
                if (dlgPicture.ShowDialog() == DialogResult.OK)
                {
                    pbxProperty.Image = Image.FromFile(dlgPicture.FileName);
                    strPictureFile = dlgPicture.FileName;
                    bPictureChanged = true;
                }
            }
    
            private void btnFind_Click(object sender, EventArgs e)
            {
                using (SqlConnection scAltairRealtors =
                        new SqlConnection("Data Source=(local);" +
                                           "Database='AltairRealtors1';" +
                                           "Integrated Security='SSPI';"))
                {
                    SqlCommand cmdProperties =
                        new SqlCommand("SELECT PropertyNumber, " +
                                       "       PropertyType, " +
                                       "       [Address], " +
                                       "       City, " +
                                       "	   [State], " +
                                       "       ZIPCode, " +
                                       "       Bedrooms, " +
                                       "       Bathrooms, " +
                                       "       Stories, " +
                                       "       FinishedBasement, " +
                                       "       IndoorGarage, " +
                                       "       YearBuilt, " +
                                       "       Condition, " +
                                       "       MarketValue, " +
                                       "       SaleStatus " +
                                       "FROM Listings.Properties " +
                                       "WHERE PropertyNumber = '" + txtPropertyNumber.Text + "';",
                                       scAltairRealtors);
    
                    cmdProperties.CommandType = CommandType.Text;
    
                    SqlDataAdapter sdaProperties = new SqlDataAdapter();
                    scAltairRealtors.Open();
    
                    DataSet dsProperties = new DataSet("PropertiesSet");
                    sdaProperties.SelectCommand = cmdProperties;
    
                    sdaProperties.Fill(dsProperties);
                    cmdProperties.ExecuteNonQuery();
    
                    foreach (DataRow house in dsProperties.Tables[0].Rows)
                    {
                        cbxPropertiesTypes.Text = house["PropertyType"].ToString();
                        txtAddress.Text = house["Address"].ToString();
                        txtCity.Text = house["City"].ToString();
                        cbxStates.Text = house["State"].ToString();
                        txtZIPCode.Text = house["ZIPCode"].ToString();
                        txtBedrooms.Text = house["Bedrooms"].ToString();
                        txtBathrooms.Text = house["Bathrooms"].ToString();
                        chkFinishedBasement.Checked = bool.Parse(house["FinishedBasement"].ToString());
                        chkIndoorGarage.Checked = bool.Parse(house["IndoorGarage"].ToString());
                        txtStories.Text = house["Stories"].ToString();
                        txtYearBuilt.Text = house["YearBuilt"].ToString();
                        cbxConditions.Text = house["Condition"].ToString();
                        txtMarketValue.Text = house["MarketValue"].ToString();
                        cbxSalesStatus.Text = house["SaleStatus"].ToString();
                    }
                }
    
                // We need to locate the picture associated
                string strDirectory = "C:\\Altair Realtors";
                // First locate the folder where the pictures records are located
                DirectoryInfo dirProperties = new DirectoryInfo(strDirectory);
                // Get a list of (only) the picture files
                FileInfo[] PictureFiles = dirProperties.GetFiles("*.jpg");
    
                // At this time, we don't know if the picture exists
                bool pictureExists = false;
    
                // Look for a file that holds the same name as the property number
                foreach (FileInfo fle in PictureFiles)
                {
                    // Get the name of the file without its extension
                    string fwe = Path.GetFileNameWithoutExtension(fle.FullName);
    
                    // If you find a picture that has the same name as the property number
                    if (fwe == txtPropertyNumber.Text)
                    {
                        // Display that picture
                        pbxProperty.Image = Image.FromFile(strDirectory + "\\" + txtPropertyNumber.Text + ".jpg");
                        pictureExists = true;
                    }
    
                    // If there is no picture that has the same name as the 
                    // property number, display the default picture
                    if (pictureExists == false)
                        pbxProperty.Image = Image.FromFile("C:\\Altair Realtors\\default.jpg");
                }
            }
        }
    }

27. Display the Altair Realtors form (the first form)
28. Add a tab control to the form and set its Anchor property to Top, Bottom, Left, Right
29. Add a list view to the first tab page
30. Right-click the list view and click Edit Groups...
31. Create the groups as follows:
     

    Header	Name
    Condominium	lvgCondominium
    Townhouse	lvgTownhouse
    Single Family	lvgSingleFamily

32. Click OK
33. Design the form as follows:
     

    Control (Name) Text Anchor Tab Page     Properties Summary   List View lvwProperties   Top, Bottom, Left     (Name) Text TextAlign Width colPropertyNumber Property #   62 colCity City   100 colBedrooms Bedrooms Right 40 colBathrooms Bathrooms Right 40 colFinishedBasement FinishedBasement Center 110 colCondition Condition   80 colYearBuilt Year Right 40 colMarketValue Market Value Right 75 colSaleStatus Status   80 Picture Box pbxProperty   Top, Bottom, Left, Right Tab Page     Real Estate Lising   Data Grid View dgvProperties   Top, Bottom, Left, Right List View lvwPropertiesStatistics Properties Statistics Bottom, Left, Right Button btnNewProperty New Real Estate Property ... Bottom, Right Button btnPropertyEditor Edit Real Estate Property ... Bottom, Right Button btnClose Close Bottom, Right

34. Right-click anywhere on the form and click View Code
35. Change the document as follows:

    internal void ShowProperties()
    {
        using (SqlConnection scAltairRealtors =
            new SqlConnection("Data Source=(local);" +
                               "Database='AltairRealtors1';" +
                               "Integrated Security='SSPI';"))
        {
            SqlCommand cmdProperties =
                new SqlCommand("SELECT props.PropertyNumber, " +
                               "       props.PropertyType, " +
                               "       props.City, " +
                               "       props.Bedrooms, " +
                               "       props.Bathrooms, " +
                               "       props.FinishedBasement, " +
                               "       props.YearBuilt, " +
                               "       props.Condition, " +
                               "       props.MarketValue, " +
                               "       props.SaleStatus " +
                               "FROM Listings.Properties props;",
                               scAltairRealtors);
            cmdProperties.CommandType = CommandType.Text;
    
            SqlDataAdapter sdaProperties = new SqlDataAdapter();
            scAltairRealtors.Open();
    
            DataSet dsProperties = new DataSet("PropertiesSet");
            sdaProperties.SelectCommand = cmdProperties;
            sdaProperties.Fill(dsProperties);
            cmdProperties.ExecuteNonQuery();
    
            lvwProperties.Items.Clear();
            lvwPropertiesStatistics.Items.Clear();
    
            foreach (DataRow house in dsProperties.Tables[0].Rows)
            {
                ListViewItem lviProperty = null;
    
                if (house["PropertyType"].ToString() == "Condominium")
                    lviProperty = new ListViewItem(house["PropertyNumber"].ToString(), lvwProperties.Groups[0]);
                else if (house["PropertyType"].ToString() == "Townhouse")
                    lviProperty = new ListViewItem(house["PropertyNumber"].ToString(), lvwProperties.Groups[1]);
                else
                    lviProperty = new ListViewItem(house["PropertyNumber"].ToString(), lvwProperties.Groups[2]);
    
                lviProperty.SubItems.Add(house["City"].ToString());
                lviProperty.SubItems.Add(house["Bedrooms"].ToString());
                lviProperty.SubItems.Add(double.Parse(house["Bathrooms"].ToString()).ToString("F"));
                lviProperty.SubItems.Add(house["FinishedBasement"].ToString());
                lviProperty.SubItems.Add(house["Condition"].ToString());
                lviProperty.SubItems.Add(house["YearBuilt"].ToString());
                lviProperty.SubItems.Add(house["MarketValue"].ToString());
                lviProperty.SubItems.Add(house["SaleStatus"].ToString());
                lvwProperties.Items.Add(lviProperty);
            }
    
            pbxProperty.Image = Image.FromFile("C:\\Altair Realtors\\default.jpg");
        }
    
        using (SqlConnection scAltairRealtors =
            new SqlConnection("Data Source=(local);" +
                               "Database='AltairRealtors1';" +
                               "Integrated Security='SSPI';"))
        {
            SqlCommand cmdProperties = new SqlCommand("SELECT props.PropertyID [Prop ID], " +
                                                      "       props.PropertyNumber [Property #], " +
                                                      "       props.PropertyType   [Type], " +
                                                      "       props.[Address], " +
                                                      "       props.City, " +
                                                      "       props.[State], " +
                                                      "       props.ZIPCode [ZIP Code], " +
                                                      "       props.Bedrooms Beds, " +
                                                      "       props.Bathrooms Baths, " +
                                                      "       props.Stories, " +
                                                      "       props.FinishedBasement [Finished Basement?], " +
                                                      "       props.IndoorGarage [Indoor Garage], " +
                                                      "       props.YearBuilt [Year Built], " +
                                                      "       props.Condition, " +
                                                      "       props.MarketValue [Market Value], " +
                                                      "       props.SaleStatus " +
                                                      "FROM Listings.Properties props;", scAltairRealtors);
            cmdProperties.CommandType = CommandType.Text;
    
            SqlDataAdapter sdaProperties = new SqlDataAdapter();
            scAltairRealtors.Open();
    
            DataSet dsProperties = new DataSet("PropertiesSet");
            sdaProperties.SelectCommand = cmdProperties;
            sdaProperties.Fill(dsProperties);
            dgvProperties.DataSource = dsProperties.Tables[0];
            cmdProperties.ExecuteNonQuery();
        }
    }
    
    private void AltairRealtors_Load(object sender, EventArgs e)
    {
        ShowProperties();
    }

36. Return to the Altair Realtors form and click the Properties Summary list view
37. In the Properties window, click Events and double-click ItemSelectionChanged
38. Implement the event as follows:

    private void lvwProperties_ItemSelectionChanged(object sender, ListViewItemSelectionChangedEventArgs e)
    {
        // Get a list of the picture files from the Altair Realtors folder
        string strDirectory = "C:\\Altair Realtors";
        DirectoryInfo dirProperties = new DirectoryInfo(strDirectory);
        FileInfo[] PictureFiles = dirProperties.GetFiles("*.jpg");
    
        bool pictureExists = false;
    
        // Look for a file that holds the same name as the property number
        foreach (FileInfo fle in PictureFiles)
        {
            // Get the name of the file without its extension
            string fwe = Path.GetFileNameWithoutExtension(fle.FullName);
    
            if (fwe == e.Item.SubItems[0].Text)
            {
                pbxProperty.Image = Image.FromFile(strDirectory + "\\" + e.Item.SubItems[0].Text + ".jpg");
                pictureExists = true;
            }
    
            if (pictureExists == false)
                pbxProperty.Image = Image.FromFile("C:\\Altair Realtors\\default.jpg");
        }
    }

39. Return to the Altair Realtors form and double-click the New Real Estate Property button
40. Implement the event as follows:

    private void btnNewProperty_Click(object sender, EventArgs e)
    {
        int iFinishedBasement = 0;
        int iIndoorGarage = 0;
        NewRealEstateProperty rep = new NewRealEstateProperty();
    
        if (rep.ShowDialog() == System.Windows.Forms.DialogResult.OK)
        {
            if (rep.chkFinishedBasement.Checked == true)
                iFinishedBasement = 1;
            if (rep.chkIndoorGarage.Checked == true)
                iIndoorGarage = 1;
    
            using (SqlConnection scAltairRealtors =
                new SqlConnection("Data Source=(local);" +
                                   "Database='AltairRealtors1';" +
                                   "Integrated Security='SSPI';"))
            {
                SqlCommand cmdProperty =
                    new SqlCommand("INSERT INTO Listings.Properties(PropertyNumber, " +
                                   "PropertyType, [Address], City, [State], ZIPCode, " +
                                   "Bedrooms, Bathrooms, Stories, FinishedBasement, " +
                                   "IndoorGarage, YearBuilt, Condition, MarketValue, " +
                                   "SaleStatus) VALUES(N'" + rep.txtPropertyNumber.Text + "', N'" +
                                   rep.cbxPropertyTypes.Text + "', N'" + rep.txtAddress.Text + "', N'" +
                                   rep.txtCity.Text + "', N'" + rep.cbxStates.Text + "', N'" +
                                   rep.txtZIPCode.Text + "', " + int.Parse(rep.txtBedrooms.Text) + ", " +
                                   float.Parse(rep.txtBathrooms.Text) + ", " +
                                   int.Parse(rep.txtStories.Text) + ", " + iFinishedBasement + ", " +
                                   iIndoorGarage + ", " + int.Parse(rep.txtYearBuilt.Text) + ", N'" +
                                   rep.cbxConditions.Text + "', " + decimal.Parse(rep.txtMarketValue.Text)
                                   + ", N'" + rep.cbxSaleStatus.Text + "');",
                                   scAltairRealtors);
    
                scAltairRealtors.Open();
                cmdProperty.ExecuteNonQuery();
    
                if (!(string.IsNullOrEmpty(rep.strPictureFile)))
                {
                    FileInfo flePicture = new FileInfo(rep.strPictureFile);
                    flePicture.CopyTo("C:\\Altair Realtors\\" + rep.txtPropertyNumber.Text + flePicture.Extension);
                }
            }
        }
    
        ShowProperties();
    }

41. Return to the Altair Realtors form and double-click the Edit Real Estate Property button
42. Implement the event as follows:

    private void btnPropertyEditor_Click(object sender, EventArgs e)
    {
        PropertyEditor editor = new PropertyEditor();
    
        using (SqlConnection scAltairRealtors =
                    new SqlConnection("Data Source=(local);" +
                                       "Database='AltairRealtors1';" +
                                       "Integrated Security='SSPI';"))
        {
            SqlCommand cmdProperty =
                new SqlCommand("UPDATE Listings.Properties SET PropertyType = N'" + editor.cbxPropertiesTypes.Text + "' WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';" +
                               "UPDATE Listings.Properties SET [Address] = N'" + editor.txtAddress.Text + "' WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';" +
                               "UPDATE Listings.Properties SET City = N'" + editor.txtCity.Text + "' WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';" +
                               "UPDATE Listings.Properties SET [State] = N'" + editor.cbxStates.Text + "' WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';" +
                               "UPDATE Listings.Properties SET ZIPCode = N'" + editor.txtZIPCode.Text + "' WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';" +
                               "UPDATE Listings.Properties SET Bedrooms = " + int.Parse(editor.txtBedrooms.Text) + " WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';" +
                               "UPDATE Listings.Properties SET Bathrooms = " + float.Parse(editor.txtBathrooms.Text) + " WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';" +
                               "UPDATE Listings.Properties SET Stories = " + int.Parse(editor.txtStories.Text) + " WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';" +
                               "UPDATE Listings.Properties SET FinishedBasement " + editor.chkFinishedBasement.Checked + " WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';" +
                               "UPDATE Listings.Properties SET IndoorGarage = " + editor.chkIndoorGarage.Checked + " WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';" +
                               "UPDATE Listings.Properties SET YearBuilt = " + int.Parse(editor.txtYearBuilt.Text) + " WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';" +
                               "UPDATE Listings.Properties SET Condition = N'" + editor.cbxConditions.Text + "' WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';" +
                               "UPDATE Listings.Properties SET MarketValue = " + decimal.Parse(editor.txtMarketValue.Text) + "' WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';" +
                               "UPDATE Listings.Properties SET SaleStatus = N'" + editor.cbxSalesStatus.Text + "' WHERE PropertyNumber = N'" + editor.txtPropertyNumber.Text + "';",
                               scAltairRealtors);
    
            scAltairRealtors.Open();
            cmdProperty.ExecuteNonQuery();
        }
    
        editor.ShowDialog();
    }

43. Return to the form and click the list view
44. Execute the application and create the properties

45. Close the form and return to your programming environment

Although you can create an aggregate query with all fields or any field(s) of a table or view, the purpose of the query is to summarize data. For a good summary query, you should select a column where the records hold categories of data. This means that the records in the resulting query have to be grouped by categories. To support this, the SQL provides the GROUP BY expression. It is added after the FROM clause. This is done as follows:

SELECT WhatField(s)
FROM WhatObject(s)
GROUP BY Column(s)

The new expression in this formula is GROUP BY. This indicates that you want to group some values from one or more columns. Of course, there are rules you must follow.

As stated already, the purpose of an aggregate query is to provide some statistics. Therefore, it is normal that you be interested only in the column(s) that hold(s) the desired statistics and avoid the columns that are irrelevant. As a result, if you select (only) the one column that holds the information you want, in the resulting list, each of its categories would display only once.

1. Display the Altair Realtors form.
   On the form, right-click the bottom list view and click Edit columns
2. Add a column with the following characteristics:
   (Name): colPropertyCategory
   Text: Property Category
   Width: 120