Anlauf 2,  Ergebnis, mit gwen3,  LM Studio


create a  delphi pascal programm with a postgres customer example database
for windows desktop



Here's a complete Windows Desktop Delphi Pascal application that demonstrates working with a PostgreSQL customer database:

```pascal
program CustomerDatabaseApp;

uses
  Vcl.Forms,
  System.SysUtils,
  FireDAC.Stan.Def,
  FireDAC.Stan.Pool,
  FireDAC.Stan.Async,
  FireDAC.Stan.Connection,
  FireDAC.Stan.Error,
  FireDAC.Phys.Intf,
  FireDAC.Phys.PGSQLDef,
  FireDAC.Phys.PGSQL,
  FireDAC.VCLUI.Wait,
  Data.DB,
  FireDAC.DApt,
  FireDAC.DApt.Intf,
  FireDAC.DatS,
  Vcl.StdCtrls,
  Vcl.ExtCtrls,
  Vcl.Controls,
  Vcl.Dialogs;

{$R *.res}

type
  TForm1 = class(TForm)
    Panel1: TPanel;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Label5: TLabel;
    EditFirstName: TEdit;
    EditLastName: TEdit;
    EditEmail: TEdit;
    EditPhone: TEdit;
    EditAddress: TEdit;
    ButtonAdd: TButton;
    ButtonUpdate: TButton;
    ButtonDelete: TButton;
    ButtonRefresh: TButton;
    DBGrid1: TDBGrid;
    DataSource1: TDataSource;
    FDConnection1: TFDConnection;
    FDQuery1: TFDQuery;
    FDQuery1id: TIntegerField;
    FDQuery1first_name: TStringField;
    FDQuery1last_name: TStringField;
    FDQuery1email: TStringField;
    FDQuery1phone: TStringField;
    FDQuery1address: TMemoField;
    FDQuery1created_at: TDateTimeField;
    procedure FormCreate(Sender: TObject);
    procedure ButtonAddClick(Sender: TObject);
    procedure ButtonUpdateClick(Sender: TObject);
    procedure ButtonDeleteClick(Sender: TObject);
    procedure ButtonRefreshClick(Sender: TObject);
    procedure DBGrid1DblClick(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    procedure LoadCustomers;
    procedure ClearFields;
    procedure SelectCustomer(const AId: Integer);
  public
  end;

var
  Form1: TForm1;

procedure TForm1.FormCreate(Sender: TObject);
begin
  // Configure PostgreSQL connection
  FDConnection1.DriverID := 'PGSQL';
  FDConnection1.Params.Clear;
  FDConnection1.Params.Add('Database=customerdb');
  FDConnection1.Params.Add('User_Name=postgres');
  FDConnection1.Params.Add('Password=mypassword');
  FDConnection1.Params.Add('Server=localhost');
  FDConnection1.Params.Add('Port=5432');
  
  try
    FDConnection1.Connected := True;
    Writeln('Connected to PostgreSQL database successfully!');
  except
    on E: Exception do
    begin
      ShowMessage('Database connection failed: ' + E.Message);
      Exit;
    end;
  end;

  // Create sample customer table if it doesn't exist
  try
    FDQuery1.SQL.Text := 
      'CREATE TABLE IF NOT EXISTS customers (' +
      'id SERIAL PRIMARY KEY, ' +
      'first_name VARCHAR(50) NOT NULL, ' +
      'last_name VARCHAR(50) NOT NULL, ' +
      'email VARCHAR(100) UNIQUE NOT NULL, ' +
      'phone VARCHAR(20), ' +
      'address TEXT, ' +
      'created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP)';
    FDQuery1.ExecSQL;
    
    // Insert sample data if table is empty
    FDQuery1.SQL.Text := 'SELECT COUNT(*) FROM customers';
    FDQuery1.Open;
    if FDQuery1.Fields[0].AsInteger = 0 then
    begin
      FDQuery1.Close;
      FDQuery1.SQL.Text := 
        'INSERT INTO customers (first_name, last_name, email, phone, address) ' +
        'VALUES ' +
        '(:fname1, :lname1, :email1, :phone1, :address1), ' +
        '(:fname2, :lname2, :email2, :phone2, :address2)';
      FDQuery1.ParamByName('fname1').Value := 'John';
      FDQuery1.ParamByName('lname1').Value := 'Doe';
      FDQuery1.ParamByName('email1').Value := 'john.doe@example.com';
      FDQuery1.ParamByName('phone1').Value := '+1234567890';
      FDQuery1.ParamByName('address1').Value := '123 Main St, City, State';
      
      FDQuery1.ParamByName('fname2').Value := 'Jane';
      FDQuery1.ParamByName('lname2').Value := 'Smith';
      FDQuery1.ParamByName('email2').Value := 'jane.smith@example.com';
      FDQuery1.ParamByName('phone2').Value := '+1234567891';
      FDQuery1.ParamByName('address2').Value := '456 Oak Ave, City, State';
      
      FDQuery1.ExecSQL;
    end;
    
    LoadCustomers;
  except
    on E: Exception do
      ShowMessage('Error setting up database: ' + E.Message);
  end;
end;

procedure TForm1.LoadCustomers;
begin
  try
    FDQuery1.Close;
    FDQuery1.SQL.Text := 'SELECT * FROM customers ORDER BY id';
    FDQuery1.Open;
  except
    on E: Exception do
      ShowMessage('Error loading customers: ' + E.Message);
  end;
end;

procedure TForm1.ClearFields;
begin
  EditFirstName.Text := '';
  EditLastName.Text := '';
  EditEmail.Text := '';
  EditPhone.Text := '';
  EditAddress.Text := '';
end;

procedure TForm1.SelectCustomer(const AId: Integer);
begin
  try
    FDQuery1.Close;
    FDQuery1.SQL.Text := 'SELECT * FROM customers WHERE id = :id';
    FDQuery1.ParamByName('id').Value := AId;
    FDQuery1.Open;
    
    if not FDQuery1.Eof then
    begin
      EditFirstName.Text := FDQuery1.FieldByName('first_name').AsString;
      EditLastName.Text := FDQuery1.FieldByName('last_name').AsString;
      EditEmail.Text := FDQuery1.FieldByName('email').AsString;
      EditPhone.Text := FDQuery1.FieldByName('phone').AsString;
      EditAddress.Text := FDQuery1.FieldByName('address').AsString;
    end;
  except
    on E: Exception do
      ShowMessage('Error selecting customer: ' + E.Message);
  end;
end;

procedure TForm1.ButtonAddClick(Sender: TObject);
begin
  try
    if (EditFirstName.Text = '') or (EditLastName.Text = '') or (EditEmail.Text = '') then
    begin
      ShowMessage('Please fill in required fields (First Name, Last Name, Email)');
      Exit;
    end;

    FDQuery1.Close;
    FDQuery1.SQL.Text := 
      'INSERT INTO customers (first_name, last_name, email, phone, address) ' +
      'VALUES (:fname, :lname, :email, :phone, :address)';
    FDQuery1.ParamByName('fname').Value := EditFirstName.Text;
    FDQuery1.ParamByName('lname').Value := EditLastName.Text;
    FDQuery1.ParamByName('email').Value := EditEmail.Text;
    FDQuery1.ParamByName('phone').Value := EditPhone.Text;
    FDQuery1.ParamByName('address').Value := EditAddress.Text;
    FDQuery1.ExecSQL;

    LoadCustomers;
    ClearFields;
    ShowMessage('Customer added successfully!');
  except
    on E: Exception do
      ShowMessage('Error adding customer: ' + E.Message);
  end;
end;

procedure TForm1.ButtonUpdateClick(Sender: TObject);
begin
  try
    if (EditFirstName.Text = '') or (EditLastName.Text = '') or (EditEmail.Text = '') then
    begin
      ShowMessage('Please select a customer to update');
      Exit;
    end;

    FDQuery1.Close;
    FDQuery1.SQL.Text := 
      'UPDATE customers SET first_name=:fname, last_name=:lname, email=:email, phone=:phone, address=:address ' +
      'WHERE id=:id';
    FDQuery1.ParamByName('fname').Value := EditFirstName.Text;
    FDQuery1.ParamByName('lname').Value := EditLastName.Text;
    FDQuery1.ParamByName('email').Value := EditEmail.Text;
    FDQuery1.ParamByName('phone').Value := EditPhone.Text;
    FDQuery1.ParamByName('address').Value := EditAddress.Text;
    FDQuery1.ParamByName('id').Value := FDQuery1.FieldByName('id').AsInteger;
    FDQuery1.ExecSQL;

    LoadCustomers;
    ClearFields;
    ShowMessage('Customer updated successfully!');
  except
    on E: Exception do
      ShowMessage('Error updating customer: ' + E.Message);
  end;
end;

procedure TForm1.ButtonDeleteClick(Sender: TObject);
begin
  try
    if (EditFirstName.Text = '') or (EditLastName.Text = '') or (EditEmail.Text = '') then
    begin
      ShowMessage('Please select a customer to delete');
      Exit;
    end;

    if MessageDlg('Are you sure you want to delete this customer?', mtConfirmation, [mbYes, mbNo], 0) = mrYes then
    begin
      FDQuery1.Close;
      FDQuery1.SQL.Text := 'DELETE FROM customers WHERE id=:id';
      FDQuery1.ParamByName('id').Value := FDQuery1.FieldByName('id').AsInteger;
      FDQuery1.ExecSQL;

      LoadCustomers;
      ClearFields;
      ShowMessage('Customer deleted successfully!');
    end;
  except
    on E: Exception do
      ShowMessage('Error deleting customer: ' + E.Message);
  end;
end;

procedure TForm1.ButtonRefreshClick(Sender: TObject);
begin
  LoadCustomers;
end;

procedure TForm1.DBGrid1DblClick(Sender: TObject);
begin
  if not FDQuery1.Eof then
  begin
    SelectCustomer(FDQuery1.FieldByName('id').AsInteger);
  end;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  FDConnection1.Connected := False;
end;

begin
  Application.Initialize;
  Application.MainFormOnTaskBar := True;
  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.
```

**To use this application:**

1. **Create a new VCL Forms Application in Delphi**
2. **Add the following components to the form:**
   - TPanel (Panel1)
   - TLabel (Label1, Label2, Label3, Label4, Label5)
   - TEdit (EditFirstName, EditLastName, EditEmail, EditPhone, EditAddress)
   - TButton (ButtonAdd, ButtonUpdate, ButtonDelete, ButtonRefresh)
   - TDBGrid (DBGrid1)
   - TDataSource (DataSource1)
   - TFDConnection (FDConnection1)
   - TFDQuery (FDQuery1)

3. **Configure the components:**
   - Set DataSource1.DataSet to FDQuery1
   - Set DBGrid1.DataSource to DataSource1
   - Set FDQuery1.Connection to FDConnection1

4. **Install Required Components:**
   - Make sure FireDAC is installed in your Delphi IDE
   - Install PostgreSQL ODBC driver or use FireDAC's native PostgreSQL support

5. **Database Setup:**
   - Create a database named `customerdb` in PostgreSQL
   - Update connection parameters:
     ```pascal
     FDConnection1.Params.Add('Database=customerdb');
     FDConnection1.Params.Add('User_Name=postgres');
     FDConnection1.Params.Add('Password=mypassword');
     ```

**Features of this Desktop Application:**

- **CRUD Operations**: Create, Read, Update, Delete customers
- **Form-based Interface**: User-friendly Windows desktop interface
- **Real-time Data Display**: DBGrid shows all customers
- **Data Validation**: Checks for required fields
- **Error Handling**: Proper exception handling with user messages
- **Auto Setup**: Automatically creates table and sample data
- **Connection Management**: Proper connection handling

**Expected Interface Layout:**
```
+-----------------------------------------------------+
| [First Name] [Last Name] [Email] [Phone] [Address] |
|                                                     |
|              [Add] [Update] [Delete] [Refresh]      |
|                                                     |
| ID | First Name | Last Name | Email            |
|----|------------|-----------|------------------|
| 1  | John       | Doe       | john.doe@email.com|
| 2  | Jane       | Smith     | jane.smith@email.com|
+-----------------------------------------------------+
```

**Requirements:**
- Delphi IDE (Community, Professional, or Enterprise)
- PostgreSQL database server
- FireDAC components installed
- PostgreSQL ODBC driver or native PostgreSQL support

The application will automatically create the customers table and insert sample data if it doesn't exist. Users can add, update, delete, and refresh customer records through the intuitive GUI interface.