procedure TForm1.btnHapusClick(Sender: TObject);
var
i :integer;
begin
   i:=0;
   while i<ListView1.Items.Count do
   if ListView1.Items.Item[i].Checked then
   ListView1.Items.Item[i].Delete
   else
   Inc(i);
end;

procedure TForm1.btnHapusClick(Sender: TObject);
var
i :integer;
begin
   i:=0;
   while i<ListView1.Items.Count do
   if ListView1.Items.Item[i].Checked then
   sql.close;
   sql.clear;
   sql.add('delete from tabelku where tabelId='+ListView1.Items.Item[i].caption);
   sql.execute;
   else
   Inc(i);
end; 

@elva_ivana: kira2 begini cara nya (silahkan di betulkan jiga ada yg lbh simpel)

procedure TForm1.btnHapusClick(Sender: TObject);
var
i :integer;
begin
   i:=0;
   while i<ListView1.Items.Count do
   if ListView1.Items.Item[i].Checked then
   sql.close;
   sql.clear;
   sql.add('delete from tabelku where tabelId='+ListView1.Items.Item[i].caption);
   sql.execute;
   // else ----> dihapus
   Inc(i);
end; 

if (listview1.Selected <> nil)  then
  begin
  i:=0;
  while i<ListView1.Items.Count do
  if ListView1.Items.Item[i].Checked=true then
  adocommand1.CommandText:='delete from invoice where description ='''+(listview1.items.item[i].checked)+''' and [invoice#]='''+(invoice.Text)+''' ';
  adocommand1.Execute;
  refreshdata;
else inc(i);
  end

if (listview1.Selected <> nil)  then
  begin
  i:=0;
  while i<ListView1.Items.Count do
  if ListView1.Items.Item[i].Checked=true then
  adocommand1.CommandText:='delete from invoice '+
'where description ='''+(listview1.items.item[i].caption)+
''' and [invoice#]='''+(invoice.Text)+''' ';
  adocommand1.Execute;
  refreshdata;
else inc(i);
  end

@elva_ivana:

if (listview1.Selected <> nil)  then
  begin
  i:=0;
  while i<ListView1.Items.Count do
  if ListView1.Items.Item[i].Checked=true then
  adocommand1.CommandText:='delete from invoice '+
'where description ='''+(listview1.items.item[i].caption)+
''' and [invoice#]='''+(invoice.Text)+''' ';
  adocommand1.Execute;
  refreshdata;
else inc(i);
  end