Question

我有一个Oracle 11g，我想知道是否可以从一个日期选择另一个日期。

例如：我有两个字段，分别为StartDate和EndDate。我想显示EndDate和StartDate之间的行数。如果我的StartDate是2018-08-01而我的EndDate是2018-08-10，那么我的期望表应该是：

DATE       | rownum
2018-08-01 | 1
2018-08-02 | 2
2018-08-03 | 3
2018-08-04 | 4
2018-08-05 | 5
2018-08-06 | 6
2018-08-07 | 7
2018-08-08 | 8
2018-08-09 | 9
2018-08-10 | 10

谢谢！

Answer 1

您可能需要如下所示的行生成器：

select date '2018-08-01' + level -1 as yourDate,
       level as yourRowNum
from dual
connect by date '2018-08-01' + level -1 <= date '2018-08-10'

结果：

YOURDATE   YOURROWNUM
---------- ----------
2018-08-01          1
2018-08-02          2
2018-08-03          3
2018-08-04          4
2018-08-05          5
2018-08-06          6
2018-08-07          7
2018-08-08          8
2018-08-09          9
2018-08-10         10

为避免重复日期值，可以使用：

with dateRange(startDate, endDate) as
(
    select date '2018-08-01', date '2018-08-10'
    from dual
)
select startDate + level -1 as yourDate,
       level as yourRowNum
from dateRange
connect by startDate + level -1 <= endDate;

Answer 2

使用sum(1) over (order by "date")可以轻松获得所需的内容：

select "Date", sum(1) over (order by "Date") "Row Number"
  from tab 
 where "Date" between date'2018-08-01' and date'2018-08-10';

Date         Row Number
----------   ----------       
2018-08-01          1
2018-08-02          2
2018-08-03          3
2018-08-04          4
2018-08-05          5
2018-08-06          6
2018-08-07          7
2018-08-08          8
2018-08-09          9
2018-08-10         10

其他替代方法count(1)，row_number()也可以替换为sum(1)。

SQL Fiddle Demo

Answer 3

我想你想要这样的东西...

WITH my_table AS
    (SELECT     TRUNC(SYSDATE) + LEVEL - 1 AS current_day
     FROM       DUAL
     CONNECT BY LEVEL < 10)
SELECT FIRST_VALUE(current_day) OVER (ORDER BY current_day) first_day
     , current_day
     , current_day - FIRST_VALUE(current_day) OVER (ORDER BY current_day) days_diff
FROM   my_TABLE;

FIRST_DAY CURRENT_DAY  DAYS_DIFF
--------- ----------- ----------
29-AUG-18 29-AUG-18            0
29-AUG-18 30-AUG-18            1
29-AUG-18 31-AUG-18            2
29-AUG-18 01-SEP-18            3
29-AUG-18 02-SEP-18            4
29-AUG-18 03-SEP-18            5
29-AUG-18 04-SEP-18            6
29-AUG-18 05-SEP-18            7
29-AUG-18 06-SEP-18            8

9 rows selected.

在两个日期之间选择范围

3 个答案: