unit1.pas

Delphi数据库编程

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, DB, DBTables, ExtCtrls, DBCtrls, Mask;

type
  TForm1 = class(TForm)
    Table1: TTable;
    DataSource1: TDataSource;
    Label1: TLabel;
    DBEdit1: TDBEdit;
    Label2: TLabel;
    DBEdit2: TDBEdit;
    Label3: TLabel;
    DBEdit3: TDBEdit;
    Label4: TLabel;
    DBEdit4: TDBEdit;
    Table2: TTable;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
    procedure Button6Click(Sender: TObject);
    procedure Button7Click(Sender: TObject);
    procedure Table1BeforeDelete(DataSet: TDataSet);
    procedure Table1AfterPost(DataSet: TDataSet);
   private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
  var
     curdir:string;
begin
     getdir(0,curdir);
     table1.Active :=False;
     table1.DatabaseName :=curdir;
     table1.Open ;
 end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  Table1.Append;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
 Table1.Insert;
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  Table1.Edit ;
end;

procedure TForm1.Button4Click(Sender: TObject);
begin
  Table1.Post ;
end;

procedure TForm1.Button5Click(Sender: TObject);
begin
  Table1.Cancel ;
end;

procedure TForm1.Button6Click(Sender: TObject);
begin
 Table1.Close ;
 application.Terminate ;
end;

procedure TForm1.Button7Click(Sender: TObject);
begin
 
  Table1.Delete ;
end;

procedure TForm1.Table1BeforeDelete(DataSet: TDataSet);
begin
  try
   Table2.IndexName :='XH';
   if Table2.FindKey([DataSet.FieldByName('学号').AsString ]) then
       raise Exception.Create('不能删除记录');
   except
     on E:EDBEngineError do
            showmessage('不能删除该记录');
  end;
end;

procedure TForm1.Table1AfterPost(DataSet: TDataSet);
begin
  Showmessage('数据保存成功');
end;

end.