unit2.pas

delphi数据库的程序代码

unit Unit2;

interface

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

type
  TForm1 = class(TForm)
    DataSource1: TDataSource;
    Query1: TQuery;
    EditName: TEdit;
    Label1: TLabel;
    DBGrid1: TDBGrid;
    BtnQuery: TButton;
    DBNavigator1: TDBNavigator;
    procedure BtnQueryClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

{
procedure TForm1.BtnQueryClick(Sender: TObject);
var
    strSql:String;
begin
    if Trim(EditName.Text)<>'' then
    begin
        //生成SQL语句时，要把文本输入框的首尾空格除去
        strSql:='Select Name,Weight,Area From animals Where Name='''
            +Trim(EditName.Text)+'''';
        //关闭记录集
        if Query1.Active then
            Query1.Active:=False;
        Query1.SQL.Clear;
        //加入SQL语句
        Query1.SQL.Add(strSql);
        //执行SQL语句
        Query1.Active:=True;
    end;
end;
}


procedure TForm1.BtnQueryClick(Sender: TObject);
begin
    if Trim(EditName.Text)<>'' then
    begin
        //关闭记录集
        if Query1.Active then
            Query1.Active:=False;
        //给参数赋值
        Query1.Params[0].AsString:=Trim(EditName.Text);
        //执行SQL语句
        Query1.Active:=True;
    end;
end;

end.