Выборка поля с БД

//---------------------------------------------------------------------------
 
#include <vcl.h>
#pragma hdrstop
 
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
    : TForm(Owner)
{
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormShow(TObject *Sender)
{
ADOTable2->Insert();
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::Button1Click(TObject *Sender)
{
ADOTable2->Post();
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::FormActivate(TObject *Sender)
{
  DBComboBox1->Clear();
 ADOTable1->First();
 while (!(ADOTable1->Eof))
     {
         DBComboBox1->Items->Add(ADOTable1Nam_B->AsString);
         ADOTable1->Next();
         }
 
 
 DBComboBox2->Clear();
 ADOTable3->First();
 while (!(ADOTable3->Eof))
     {
         DBComboBox2->Items->Add( ADOTable3Mark_B->AsString);
          ADOTable3->Next();
         }
}
//---------------------------------------------------------------------------

select * from table1 where nazvanie='"+combobox1->Text+"' and marka='"+combobox2->Text"';"

ADOQuery1->Open();