怎樣對一個查詢得到的結果再進行操作﹐如對查詢結果集的某個字段值求累計和﹖

Question

procedure TForm1.Button3Click(Sender: TObject);
VAR SUMS:REAL;
begin
  QUERY1.OPEN
  QUERY1.First;
  SUMS:=0;
  WHILE NOT QUERY1.Eof DO
       BEGIN
         SUMS:=SUMS+QUERY1.FieldValues['YOURFIELD'];
         QUERY1.Next;
       END;
  SHOWMESSAGE('累計和为'+FLOATTOSTR(SUMS));
end;

Answer 1

begin
  QUERY1.Close,
  QUERY1.sql.clear;
  query1.sql.add('select sum(table.field) as total,table .Num 
                  from  table group by table.Num');  Query1.prepare;
  Query1.open;
end;
begin
  Query2.close;
  Query2.sql.clear;
  Query2.Sql.add(' select * from table');
  Query2.prepare;
  Query2.open;
end;