Oracle sum group by date range - oracle

Question

I have the following table
+-----------+-------+-------+
| Date | Type | Value |
+-----------+-------+-------+
| 1/1/2013 | A | 1 |
| 1/2/2013 | A | 3 |
| 1/3/2013 | A | 5 |
| 1/4/2013 | A | 6 |
| 1/6/2013 | A | 8 |
| 1/7/2013 | A | 1 |
| 1/8/2013 | A | 2 |
+-----------+-------+-------+
I want to sum the value for the previous 3 dates for a certain day so i used this query.
ie: sel_date = 1/3/2013.
select type, sum(value)
from table_name
where date <= seldate
and date > seldate - 3
group by type
Now the problem is, I want to output a table with a given date range computing for the previous 3 days for each date.
ie: sel_date range 1/3/2013 - 1/8/2013
+-----------+-------+------------+
| Date | Type | Sum(Value) |
+-----------+-------+------------+
| 1/3/2013 | A | 9 | // 5 + 3 + 1
| 1/4/2013 | A | 14 | // 6 + 5 + 3
| 1/5/2013 | A | 11 | // 0 + 6 + 5
| 1/6/2013 | A | 14 | // 8 + 0 + 6
| 1/7/2013 | A | 9 | // 1 + 8 + 0
| 1/8/2013 | A | 11 | // 2 + 1 + 8
+-----------+-------+------------+
Is there a way to do this in a single query. I tried reading on partitioning but it is leading me no where.

Answer 1

Use range between in windowing clause:
select dt, type, value,
sum(value) over (order by dt range between 2 preceding and current row) as sv
from t
Test data and output:
create table t (dt date, type varchar2(1), value number(5));
insert into t values (date '2013-01-01', 'A', 1);
insert into t values (date '2013-01-02', 'A', 3);
insert into t values (date '2013-01-03', 'A', 5);
insert into t values (date '2013-01-04', 'A', 6);
insert into t values (date '2013-01-05', 'A', 8);
insert into t values (date '2013-01-06', 'A', 1);
insert into t values (date '2013-01-07', 'A', 2);
insert into t values (date '2013-01-12', 'A', 2);
DT TYPE VALUE SV
----------- ---- ------ ----------
2013-01-01 A 1 1
2013-01-02 A 3 4
2013-01-03 A 5 9
2013-01-04 A 6 14
2013-01-05 A 8 19
2013-01-06 A 1 15
2013-01-07 A 2 11
2013-01-12 A 2 2

Answer 2

You can try with something like this:
with test(Date_, Type, Value ) as
(
select to_date('01/01/2013', 'mm/dd/yyyy'), 'A', 1 from dual union all
select to_date('01/02/2013', 'mm/dd/yyyy'), 'A', 3 from dual union all
select to_date('01/03/2013', 'mm/dd/yyyy'), 'A', 5 from dual union all
select to_date('01/04/2013', 'mm/dd/yyyy'), 'A', 6 from dual union all
select to_date('01/05/2013', 'mm/dd/yyyy'), 'A', 8 from dual union all
select to_date('01/06/2013', 'mm/dd/yyyy'), 'A', 1 from dual union all
select to_date('01/07/2013', 'mm/dd/yyyy'), 'A', 2 from dual
)
select *
from (
select date_, type,
value + nvl(lag(value, 1) over (partition by type order by date_), 0)
+ nvl(lag(value, 2) over (partition by type order by date_), 0) as value
from test
)
where date_ between to_date('01/03/2013', 'mm/dd/yyyy') and to_date('01/07/2013', 'mm/dd/yyyy')
This sums, for each row, the values of the two preceding ones, based on date; the external query is simply used to apply the filter, given that applying it in the internal query would lead to a wrong sum.
The LAG is used to read values from the rows that precede the current row by 1 or 2 positions.

Answer 3

You can use this:
select date1 ,type,
(select sum(t1.value) sumvalue from table_name t1 where t1.date1 between (t2.date1 - 2) and t2.date1 )
from table_name t2
where date1 between startDate and endDate

Answer 4

select t.date, sum(t.value) OVER(ORDER BY t.date ROWS BETWEEN 2 PRECEDING AND 0 FOLLOWING) as Pre_3row_sum
from table_name t