Title: Set filter for database
You may use Filter and Filtered properties of Table component. But for more difficult queries, you may use OnFilterRecord event of TTable.
This example shows, how to show records, where AREA1500000.
procedure TForm1.Table1FilterRecord(DataSet: TDataSet;
var Accept: Boolean);
var
Value: Integer;
begin
Value:=Table1['Area'];
Accept:=Value>1500000;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
Table1.Filtered:=True;
end;