我想在想把过去一个时间段（比如10天）内的数据一个合计，
id total time
1 100 2015/01/01
2 101 2015/01/05
3 83 2015/01/05
4 106 2015/01/08
5 99 2015/01/19
6 190 2015/01/21
7 60 2015/01/22
如果我这样写
select
sum(total)
from tt
where time>= trunc(to_date('2015/01/10 00:00' ,'yyyy/MM/dd HH24:mi:ss') - 10)
and time< trunc(to_date('2015/01/10 00:00' ,'yyyy/MM/dd HH24:mi:ss'))
group by time
这样写的话，数据就是
100
184
83
但我需要的是不管有没有这一天，都要算上，
100
0
0
0
184
0
0
106
0
0
但是这个SQL语句怎么写呢
------解决思路----------------------
select b.time, sum(total)
from tt
right join (select to_date('2015/01/10 00:00', 'yyyy/mm/dd hh24:mi:ss') -
rownum + 1 time
from dual
connect by level <= 10) b
on b.time = tt.time
and tt.time >=
trunc(to_date('2015/01/10 00:00', 'yyyy/MM/dd HH24:mi:ss') - 10)
and tt.time <
trunc(to_date('2015/01/10 00:00', 'yyyy/MM/dd HH24:mi:ss'))
group by b.time
order by 1;