Как сравнить две таблицы dbe на предмет одинаковых записей по определенным полям

procedure TForm1.Button1Click(Sender: TObject);
begin
  with DataModule1.ZQuery1 do
  begin
    Close;
    SQL.Clear;
    SQL.Add('UPDATE t2 SET unik = null');
    ExecSQL;
    Close;
    SQL.Clear;
    SQL.Add(
      'UPDATE t2 SET unik = 1 WHERE name IN (SELECT DISTINCT t1.name FROM t1 INNER JOIN t2 ON (t1.name = t2.name))');
    ExecSQL;
    Close;
  end;
  DataModule1.ZTable2.Refresh;
end;
 
procedure TForm1.DBGrid2DrawColumnCell(Sender: TObject; const Rect: TRect;
  DataCol: integer; Column: TColumn; State: TGridDrawState);
begin
  if DataModule1.ZTable2.FieldByName('unik').Value = 1 then
    begin
      TDBGrid(Sender).Canvas.Font.Color := clWhite;
      TDBGrid(Sender).Canvas.Brush.Color := clRed;
      TDBGrid(Sender).Canvas.FillRect(Rect);
    end;
  if gdSelected in State then
  begin
    TDBGrid(Sender).Canvas.Font.Color := clHighLightText;
    TDBGrid(Sender).Canvas.Brush.Color := clHighlight;
    TDBGrid(Sender).Canvas.FillRect(Rect);
  end;
  TDBGrid(Sender).DefaultDrawColumnCell(Rect, DataCol, Column, State);
end;

procedure TForm1.ToolButton19Click(Sender: TObject);
begin
  if Table2.Locate('Naimenovanie;Countru;Series;Year',
     VarArrayOf([Table1.FieldByName('Naimenovanie').Value, Table1.FieldByName('Countru').Value,
     Table1.FieldByName('Series').Value,Table1.FieldByName('Year').Value]),[loCaseInsensitive, loPartialKey]) then
     begin
     Table2.Edit;
     Table2.FieldByName('Same').Value:=1;
     Table2.Post;
     end
    else
      ShowMessage('Данной записи нет')
end;

procedure TForm1.cxGridDBTableView1CustomDrawCell(
  Sender: TcxCustomGridTableView; ACanvas: TcxCanvas;
  AViewInfo: TcxGridTableDataCellViewInfo; var ADone: Boolean);
var
  ARec: TRect;
  val: string;
begin
  ARec := AViewInfo.Bounds;
  val := VarAsType(AViewInfo.GridRecord.DisplayTexts[cxGridDBTableView1Same.index], varString);
  if val = '1' then
    begin
     ACanvas.Canvas.Brush.Color := $B9B9FF;
     ACanvas.Canvas.FillRect(ARec);
    end;
end;

 with DataModule1.ZQuery1 do
  begin
    Close;
    SQL.Clear;
    SQL.Add('UPDATE t2 SET unik = null');
    ExecSQL;
    Close;
    SQL.Clear;
    SQL.Add(
      'UPDATE t2 SET unik = 1 WHERE name IN (SELECT DISTINCT t1.name FROM t1 INNER JOIN t2 ON (t1.name = t2.name))');
    ExecSQL;
    Close;
  end;

table1.first;
while not table1.eof do
  begin
    if Table2.Locate('Naimenovanie;Countru;Series;Year',
     VarArrayOf([Table1.FieldByName('Naimenovanie').Value, Table1.FieldByName('Countru').Value,
     Table1.FieldByName('Series').Value,Table1.FieldByName('Year').Value]),[loCaseInsensitive, loPartialKey]) then
    begin
      Table2.Edit;
      Table2.FieldByName('Same').Value:=1;
      Table2.Post;
    end;
    table1.next;
  end;

 table1.first;
progressbar1.min:= 0;
progressbar1.Max:= table1.rowcount; 
progressbar1.position:= 0;
while not table1.eof do
  begin
    progressbar1.position:= progressbar1.position + 1;
    if Table2.Locate('Naimenovanie;Countru;Series;Year',
     VarArrayOf([Table1.FieldByName('Naimenovanie').Value, Table1.FieldByName('Countru').Value,
     Table1.FieldByName('Series').Value,Table1.FieldByName('Year').Value]),[loCaseInsensitive, loPartialKey]) then
    begin
      Table2.Edit;
      Table2.FieldByName('Same').Value:=1;
      Table2.Post;
    end;
    table1.next;
  end;

procedure TForm1.ToolButton20Click(Sender: TObject);
begin
Table1.first;
cxProgressBar1.Position:= 0;
cxProgressBar1.Properties.Min:=0;
cxProgressBar1.Properties.Max:=Table1.FieldCount;
while not Table1.eof do
  begin
    cxProgressBar1.position:=Table1.RecordCount + 1;
    if Table2.Locate('Naimenovanie;Countru;Series;Year',
     VarArrayOf([Table1.FieldByName('Naimenovanie').Value, Table1.FieldByName('Countru').Value,
     Table1.FieldByName('Series').Value,Table1.FieldByName('Year').Value]),[loCaseInsensitive, loPartialKey]) then
    begin
      Table2.Edit;
      Table2.FieldByName('Same').Value:=1;
      Table2.Post;
    end
    else
      Table2.Edit;
      Table2.FieldByName('Same').Value:=0;
      Table2.Post;
    end;
    table1.next;
end;

Application.ProcessMessages;

cxProgressBar1.Properties.Min:=0;
cxProgressBar1.Properties.Max:=Table1.RecordCount;
cxProgressBar1.Position:= 0;
while not VolgaTable1.eof do
  begin
    cxProgressBar1.position:= cxProgressBar1.position + 1;
    Application.ProcessMessages;

while not Table2.eof do
  begin    
    if Table1.Locate
      (
        'Naimenovanie;Countru;Series;Year',
        VarArrayOf(
          [Table2.FieldByName('Naimenovanie').Value,
          Table2.FieldByName('Countru').Value,
          Table2.FieldByName('Series').Value,
          Table2.FieldByName('Year').Value]),
        [loCaseInsensitive, loPartialKey]
      )
    then
      begin
        Table2.Edit;
        Table2.FieldByName('Same').Value:=1;
        Table2.Post;
      end
    else
      begin
        Table2.Edit;
        Table2.FieldByName('Same').Value:=0;
        Table2.Post;
      end;
    Table2.next;
  end;