实例——创建数据库.txt

Delphi 7组件应用实例 书籍语言： 简体中文 书籍类型： 程序设计 授权方式： 免费软件 书籍大小： 105 KB

unit U_Db;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DB, IBDatabase, StdCtrls, FileCtrl;

type
  TFdb = class(TForm)
    IBDatabase1: TIBDatabase;
    Button1: TButton;
    Edit1: TEdit;
    DriveComboBox1: TDriveComboBox;
    DirectoryListBox1: TDirectoryListBox;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Label5: TLabel;
    Edit2: TEdit;
    Memo1: TMemo;
    Label6: TLabel;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Fdb: TFdb;

implementation

{$R *.dfm}

procedure TFdb.Button1Click(Sender: TObject);
var
  result:integer;
  dest:integer;
  filename:String;
begin
//检验SQL方言的有效性
  Val( Edit2.Text,dest,result);
  if result<>0 then
    begin
      ShowMessage('SQL方言必须为整数，请重新输入！');
      exit;
    end;
  //获取用户设置的文件名，并判断其有效性
  filename := DirectoryListBox1.Directory + '\'+ Edit1.Text +'.gdb';
  if FileExists(filename) then
    begin
      ShowMessage('你所设置的文件已存在，请重新输入！');
      exit;
    end;

  // 创建数据库
  IBDatabase1.DatabaseName :=filename;
  IBDatabase1.SQLDialect := dest;
  IBDatabase1.Params := Memo1.Lines;

  try
    IBDatabase1.CreateDatabase;
    Button2.Enabled :=True;      //激活删除数据库按钮
  except
    ShowMessage('你所设置的数据库参数有误，创建失败！');
  end;

end;

procedure TFdb.Button2Click(Sender: TObject);
begin
    IBDatabase1.DropDatabase;     //删除数据库
    Button2.Enabled :=False;       //禁用删除数据库按钮
end;

procedure TFdb.FormCreate(Sender: TObject);
begin
Button2.Enabled :=False;
end;

end.