应用TADOConnection和TADODataSet组件

最新推荐文章于 2016-10-15 19:11:05 发布

原创最新推荐文章于 2016-10-15 19:11:05 发布 · 515 阅读

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#数据库 #forms #windows #class

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本文介绍了一个使用Delphi编写的单元，通过ADO组件实现数据库连接及数据展示的方法。该单元包含了一个表单，上面集成了数据库连接控件及数据网格控件，用于显示客户和订单信息。

unit U_AdoDataSet;
interface
uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  DB, ADODB, Grids, DBGrids, StdCtrls, ExtCtrls;
type
  TF_AdoDataSet = class(TForm)
    ADOConnection1: TADOConnection;
    Orders: TADODataSet;
    CustSource: TDataSource;
    OrderSource: TDataSource;
    DBGrid1: TDBGrid;
    DBGrid2: TDBGrid;
    OrdersOrderNo: TFloatField;
    OrdersCustNo: TFloatField;
    OrdersSaleDate: TDateField;
    OrdersShipDate: TDateField;
    OrdersEmpNo: TIntegerField;
    OrdersShipToContact: TWideStringField;
    OrdersShipToAddr1: TWideStringField;
    OrdersShipToAddr2: TWideStringField;
    OrdersShipToCity: TWideStringField;
    OrdersShipToState: TWideStringField;
    OrdersShipToZip: TWideStringField;
    OrdersShipToCountry: TWideStringField;
    OrdersShipToPhone: TWideStringField;
    OrdersShipVIA: TWideStringField;
    OrdersPO: TWideStringField;
    OrdersTerms: TWideStringField;
    OrdersPaymentMethod: TWideStringField;
    OrdersItemsTotal: TFloatField;
    OrdersTaxRate: TFloatField;
    OrdersFreight: TFloatField;
    OrdersAmountPaid: TFloatField;
    Panel1: TPanel;
    Edit2: TEdit;
    Edit3: TEdit;
    ShowButton: TButton;
    Customers: TADODataSet;
    CustomersCustNo: TFloatField;
    CustomersCompany: TWideStringField;
    CustomersAddr1: TWideStringField;
    CustomersAddr2: TWideStringField;
    CustomersCity: TWideStringField;
    CustomersState: TWideStringField;
    CustomersZip: TWideStringField;
    CustomersCountry: TWideStringField;
    CustomersPhone: TWideStringField;
    CustomersFAX: TWideStringField;
    CustomersTaxRate: TFloatField;
    CustomersContact: TWideStringField;
    CustomersLastInvoiceDate: TDateField;
    CustomersOrders: TDataSetField;
    CheckBox1: TCheckBox;
    Label3: TLabel;
    Label2: TLabel;
    Edit1: TEdit;
    Label1: TLabel;
    procedure ShowButtonClick(Sender: TObject);
    procedure CheckBox1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  F_AdoDataSet: TF_AdoDataSet;

implementation

{$R *.dfm}

procedure TF_AdoDataSet.ShowButtonClick(Sender: TObject);
const
  ConnStr = 'Provider=%s;Data Provider=%s;Data Source=%s';
begin
//如果用户选中复选框，那么利用三个编辑框中的文本建立与数据库的连接；
  if checkbox1.Checked then
    begin
       ADOConnection1.Close;
       ADOConnection1.ConnectionString :=  Format(ConnStr, [Edit1.Text,
           Edit2.Text,Edit3.Text]);
       ADOConnection1.Open;
    end;
 //如果数据库尚未连接，则建立与数据库的连接
  if not ADOConnection1.Connected then
    begin
        ADOConnection1.ConnectionString := Format(ConnStr, [Edit1.Text,
            Edit2.Text,Edit3.Text]);
        ADOConnection1.Open;
    end;
  Customers.Open;
  Orders.Open;
end;

procedure TF_AdoDataSet.CheckBox1Click(Sender: TObject);
begin
  if checkbox1.Checked then
    begin
      Label1.Enabled :=true; Edit1.Enabled :=true;
      Label2.Enabled :=true; Edit2.Enabled :=true;
      Label3.Enabled :=true; Edit3.Enabled :=true;
    end
  else
    begin
      Label1.Enabled :=false; Edit1.Enabled :=false;
      Label2.Enabled :=false; Edit2.Enabled :=false;
      Label3.Enabled :=false; Edit3.Enabled :=false;
    end;
end;

procedure TF_AdoDataSet.FormCreate(Sender: TObject);
begin
      Label1.Enabled :=false; Edit1.Enabled :=false;
      Label2.Enabled :=false; Edit2.Enabled :=false;
      Label3.Enabled :=false; Edit3.Enabled :=false;
end;

end.