unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    DBNavigator1: TDBNavigator;
    Query1: TQuery;
    Button1: TButton;
    Label1: TLabel;
    Edit1: TEdit;
    Query1Name: TStringField;
    Query1Capital: TStringField;
    Query1Continent: TStringField;
    Query1Area: TFloatField;
    Query1Population: TFloatField;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
begin
  Query1.Close;
  if not Query1.Prepared then
    Query1.Prepare;
  Query1.ParamByName('Name_param').Value:=Edit1.Text;
  Query1.Open;
end;

end.