[[Caral]]

Hola

Código Delphi [-]
procedure TForm1.ComboBox1Change(Sender: TObject);
var A: String;
begin
  A:= Combobox1.text;
  with ADOQuery1 do
  begin
    Close;
    SQL.Text:= 'SELECT * FROM MITABLA WHERE ANIO = :dato';
    Parameters[0].Value := QuotedStr(A);
    Open;
  end;
end;

o

Código Delphi [-]
procedure TForm1.ComboBox1Change(Sender: TObject);
var A: String;
begin
  A:= QuotedStr(Combobox1.text);
  with ADOQuery1 do
  begin
    Close;
    SQL.Text:= 'SELECT * FROM MITABLA WHERE ANIO = :dato';
    Parameters[0].Value := A;
    Open;
  end;
end;

Saludos