Oracle SQL。获取两个日期之间的日期

Question

我有一个有两个日期列的表格，如何获取这两个日期之间的日期并一一列出。 这是测试脚本：

CREATE TABLE t1
   AS
      SELECT DATE '2020-1-31' AS startdate,
             DATE '2020-2-3' AS enddate
      FROM dual
      UNION
      SELECT DATE '2020-2-27' AS startdate,
             DATE '2020-3-3' AS enddate
      FROM dual;

SELECT *
FROM t1;


DROP TABLE t1;

我期待的结果集是：

我该如何查询？ 预先感谢。

Answer 1

给你：

SQL> select * From t1;

STARTDATE  ENDDATE
---------- ----------
01/31/2020 02/03/2020
02/27/2020 03/03/2020

SQL> select a.startdate, a.enddate,
  2    a.startdate + column_value - 1 dt
  3  from t1 a cross join
  4    table(cast(multiset(select level from dual
  5                        connect by level <= a.enddate - a.startdate + 1
  6                       ) as sys.odcinumberlist))
  7  order by dt;

STARTDATE  ENDDATE    DT
---------- ---------- ----------
01/31/2020 02/03/2020 01/31/2020
01/31/2020 02/03/2020 02/01/2020
01/31/2020 02/03/2020 02/02/2020
01/31/2020 02/03/2020 02/03/2020
02/27/2020 03/03/2020 02/27/2020
02/27/2020 03/03/2020 02/28/2020
02/27/2020 03/03/2020 02/29/2020
02/27/2020 03/03/2020 03/01/2020
02/27/2020 03/03/2020 03/02/2020
02/27/2020 03/03/2020 03/03/2020

10 rows selected.

SQL>

这被称为行生成器技术（如果你也想用谷歌搜索）。

Answer 2

替代解决方案

创建表格 -

create table mytable(start_date date, end_date date);

加载数据 -

insert into mytable values (to_date('01/31/2020','mm/dd/yyyy'),to_date('02/03/2020','mm/dd/yyyy'));

SQL 检索给定日期范围之间的日期列表 -

select
   t.start_date + rownum -1 as dt,
   t.start_date,
   t.end_date
from
   all_objects, mytable t
where
   rownum <=
   t.end_date- t.start_date+1;

db 小提琴 - https://dbfiddle.uk/?rdbms=oracle_11.2&fiddle=7cd81f5892ad195b72ee1d22a3b44e2a

Answer 3

对于实际的 Oracle 版本：

SELECT *
FROM t1,
     lateral(
           select level N,
                  t1.startdate+level-1 dt
           from dual
           connect by level <= t1.enddate - t1.startdate + 1
     );

或

SELECT 
  startdate,
  enddate,
  startdate+n as DT
FROM t1,
     xmltable('0 to xs:integer(.)' 
              passing cast(enddate-startdate as number)
               columns n int path '.'
             )

完整示例：

with t1
   AS (
      SELECT DATE '2020-1-31' AS startdate,
             DATE '2020-2-3' AS enddate
      FROM dual
      UNION
      SELECT DATE '2020-2-27' AS startdate,
             DATE '2020-3-3' AS enddate
      FROM dual
)
SELECT *
FROM t1,
     lateral(
           select level N,
                  t1.startdate+level-1 dt
           from dual
           connect by level <= t1.enddate - t1.startdate + 1
     );

with t1
   AS (
      SELECT DATE '2020-1-31' AS startdate,
             DATE '2020-2-3' AS enddate
      FROM dual
      UNION
      SELECT DATE '2020-2-27' AS startdate,
             DATE '2020-3-3' AS enddate
      FROM dual
)
SELECT 
  startdate,
  enddate,
  startdate+n as DT
FROM t1,
     xmltable('0 to xs:integer(.)' 
              passing cast(enddate-startdate as number)
               columns n int path '.'
             );

Answer 4

要生成日期之间的日期列表，这是最简单的方法：

以2024年10月1日到2024年10月30日为例，将生成30条日期记录。

SELECT TRUNC(DATE '2024-10-01')-1 + LEVEL, LEVEL 
FROM DUAL CONNECT BY LEVEL < ABS(DATE '2024-10-01' - DATE '2024-11-01') -- Specify Date range here this will just result in a int for number of days
ORDER BY LEVEL

如果您需要10月1日至11月1日（含），只需按条件连接即可<= instead of <

或者如果您想从起始日期生成 10 条日期记录：

SELECT TRUNC(DATE '2024-10-01')-1 + LEVEL, LEVEL 
FROM DUAL CONNECT BY LEVEL <= 10
ORDER LEVEL

简单，不需要特殊的oracle版本。