procedure TForm1.btnDoSumClick(Sender: TObject);var i: Integer;begin if DBGrid1.SelectedRows.Count > 0 then begin with DBGrid1.DataSource.DataSet do begin for i := 0 to DBGrid1.SelectedRows.Count-1 do begin GotoBookmark(Poin…
示例 Product 表结构: 示例 Product 表数据: 想要的效果是,以 GroupName 字段分组,取出分组中通过 Sort 降序最新的数据,通过示例数据,可以推算出结果数据的 ID 应该为:7.5.3. 示例 SQL 代码: select * from Product p where ID=(select top 1 ID from Product where p.GroupName=GroupName order by Sort desc) order by Sort desc…