求一个PL/SQL的语句
有一个数据表，想求出每天的日汇总金额，FLD_TRADE_TIME这个是长日期型字段，用以下的语句最后分组成一天多条记录了，没有达到要求一天一个合计数
select fld_trade_time,sum(fld_preferential_money) from tb_bike_trade_file
where fld_trade_time >= to_date('01-09-2012', 'dd-mm-yyyy') AND fld_trade_time <= to_date('31-10-2012', 'dd-mm-yyyy') GROUP BY fld_trade_time order by fld_trade_time
[解决办法]
select trunc(fld_trade_time), sum(fld_preferential_money)
from tb_bike_trade_file
GROUP BY trunc(fld_trade_time)
order by trunc(fld_trade_time)
