Oracle sum 按日期范围分组

Question

我有下表

+-----------+-------+-------+
| 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     |
+-----------+-------+-------+

我想对某一天前 3 个日期的值求和，所以我使用了这个查询。 即：sel_date = 2013 年 1 月 3 日。

select type, sum(value)
from table_name
where date <= seldate
and date > seldate - 3
group by type

现在的问题是，我想输出一个给定日期范围的表格，计算每个日期的前 3 天。

即：sel_date 范围 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
+-----------+-------+------------+

有没有办法在单个查询中做到这一点。我尝试阅读有关分区的内容，但它让我无处可去。

Answer 1

在窗口子句中使用range between：

select dt, type, value, 
       sum(value) over (order by dt range between 2 preceding and current row) as sv
  from t

测试数据和输出：

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

你可以试试这样的：

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')

这会根据日期对每一行的前两行的值求和；外部查询仅用于应用过滤器，因为在内部查询中应用它会导致错误的总和。

LAG 用于从当前行之前 1 或 2 个位置的行中读取值。

Answer 3

你可以用这个：

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