Project Structure

• DdlSample.dpr
• DdlForm.pas
• DdlForm.dfm

program DdlSample;

uses
  Forms,
  DdlForm in 'DdlForm.pas' {Form1};

{$R *.RES}

begin
  Application.Initialize;
  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.

unit DdlForm;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ExtCtrls, DBTables, Db;

type
  TForm1 = class(TForm)
    Query1: TQuery;
    Database1: TDatabase;
    grpCommands: TRadioGroup;
    Memo1: TMemo;
    Button1: TButton;
    Button2: TButton;
    Label1: TLabel;
    procedure grpCommandsClick(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

const
  MaxCmds = 6;
  Commands: array [0..MaxCmds - 1] of PChar = (
    'CREATE TABLE Customers ('#13'  CUST_NO INTEGER NOT NULL CONSTRAINT CUST_PK PRIMARY KEY,'#13'  FIRSTNAME VARCHAR(30) NOT NULL,'#13'  LASTNAME VARCHAR(30) NOT NULL,'#13'  ADDRESS VARCHAR(30),'#13'  PHONE_NUMBER VARCHAR(20)'#13');'            ,
    'ALTER TABLE Customers DROP CONSTRAINT CUST_PK',
    'CREATE INDEX CUST_NAME ON CUSTOMERS (NAME);',
    'CREATE VIEW FullCustNames (FullName) AS'#13'SELECT (Name || " " || Surname) FROM Customers'  ,
    'CREATE GENERATOR custno_generator;',
    'CREATE TRIGGER SET_CUST_NO FOR CUSTOMERS'#13'BEFORE INSERT POSITION 0 AS'#13'BEGIN'#13'   new.cust_no = gen_id(custno_generator, 1);'#13'END'
          );

procedure TForm1.grpCommandsClick(Sender: TObject);
begin
  Memo1.Lines.SetText(Commands[grpCommands.ItemIndex]);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  Close;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  Query1.SQL.Assign(Memo1.Lines);
  try
    Query1.ExecSQL;
    ShowMessage('SQL command executed successfully.');
  except
    raise;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  grpCommandsClick(nil);
end;

end.

object Form1: TForm1
  Left = 198
  Top = 144
  BorderStyle = bsDialog
  Caption = 'SQL''s Data Definition Language Commands sample'
     ClientHeight = 254
  ClientWidth = 480
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'MS Sans Serif'
  Font.Style = []
  OldCreateOrder = False
  Position = poDesktopCenter
  OnCreate = FormCreate
  PixelsPerInch = 96
  TextHeight = 13
  object Label1: TLabel
    Left = 5
    Top = 2
    Width = 472
    Height = 29
    AutoSize = False
    Caption =
       'WARNING: it''s not safe to allow client applications to execute D'    +
      'DL commands! Users may seriously corrupt the database.'
    Font.Charset = DEFAULT_CHARSET
    Font.Color = clRed
    Font.Height = -11
    Font.Name = 'MS Sans Serif'
    Font.Style = [fsBold]
    ParentFont = False
    WordWrap = True
  end
  object grpCommands: TRadioGroup
    Left = 4
    Top = 33
    Width = 157
    Height = 183
    Caption = 'DDL Command'
    ItemIndex = 0
    Items.Strings = (
      'CREATE TABLE'
      'ALTER TABLE'
      'CREATE INDEX'
      'CREATE VIEW'
      'CREATE GENERATOR'
      'CREATE TRIGGER')
    TabOrder = 0
    OnClick = grpCommandsClick
  end
  object Memo1: TMemo
    Left = 164
    Top = 38
    Width = 313
    Height = 210
    TabOrder = 1
  end
  object Button1: TButton
    Left = 4
    Top = 223
    Width = 75
    Height = 25
    Caption = '&Execute!'
    TabOrder = 2
    OnClick = Button1Click
  end
  object Button2: TButton
    Left = 84
    Top = 223
    Width = 75
    Height = 25
    Caption = '&Close'
    TabOrder = 3
    OnClick = Button2Click
  end
  object Query1: TQuery
    DatabaseName = 'AppDB'
    Left = 132
    Top = 187
  end
  object Database1: TDatabase
    AliasName = 'IBLOCAL'
    DatabaseName = 'AppDB'
    Params.Strings = (
      'USER NAME=SYSDBA'
      'PASSWORD=masterkey'
      'OPEN MODE=READ/WRITE'
      'SCHEMA CACHE SIZE=8'
      'SQLPASSTHRU MODE=SHARED AUTOCOMMIT'
      'SCHEMA CACHE TIME=-1'
      'MAX ROWS=-1'
      'BATCH COUNT=200'
      'ENABLE SCHEMA CACHE=FALSE'
      'SCHEMA CACHE DIR='
      'ENABLE BCD=FALSE'
      'BLOBS TO CACHE=64'
      'BLOB SIZE=32')
    SessionName = 'Default'
    Left = 104
    Top = 187
  end
end