如何提取范围内的日期？

Question

我有一个 table (SQL Server 2017) 包含日期范围内的数据。

+---------+----------+------------+---------------+-------------+
| good_id | store_id | promo_name | date_id_begin | date_id_end |
+---------+----------+------------+---------------+-------------+
| 1122    | 42       | promo_1    | 2020-02-01    | 2020-02-05  |
+---------+----------+------------+---------------+-------------+
| 2244    | 41       | promo_2    | 2020-03-01    | 2020-03-03  |
+---------+----------+------------+---------------+-------------+

我需要在期间内按天获取此数据。

+---------+----------+------------+---------------+
| good_id | store_id | promo_name | date_id_begin |
+---------+----------+------------+---------------+
| 1122    | 42       | promo_1    | 2020-02-01    |
+---------+----------+------------+---------------+
| 1122    | 42       | promo_1    | 2020-02-02    |
+---------+----------+------------+---------------+
| 1122    | 42       | promo_1    | 2020-02-03    |
+---------+----------+------------+---------------+
| 1122    | 42       | promo_1    | 2020-02-04    |
+---------+----------+------------+---------------+
| 1122    | 42       | promo_1    | 2020-02-05    |
+---------+----------+------------+---------------+
| 2244    | 41       | promo_2    | 2020-03-01    |
+---------+----------+------------+---------------+
| 2244    | 41       | promo_2    | 2020-03-02    |
+---------+----------+------------+---------------+
| 2244    | 41       | promo_2    | 2020-03-03    |
+---------+----------+------------+---------------+

我可以从循环内的范围中提取日期，但是我如何select其他信息（good_id、store_id、promo_name）？

Answer 1

一个选项是递归查询：

with cte as (
    select good_id, store_id, promo_name, date_id_begin, date_id_end
    from mytable
    union all
    select good_id, store_id, promo_name, dateadd(day, 1, date_id_begin), date_id_end
    from cte 
    where date_id_begin < date_id_end
)
select good_id, store_id, promo_name, date_id_begin from cte

如果范围超过 100 天，则需要在查询末尾添加 option(max_recursion 0)。

Answer 2

如果您没有日历或计数 table，您可以使用临时计数 table。

例子

Select A.[good_id]
      ,A.[store_id]
      ,A.[promo_name] 
      ,[Date] = B.D
 From  YourTable A
 Join  (
         Select Top (25000) D=DateAdd(DAY,Row_Number() Over (Order By (Select Null)),'1999-12-31') From  master..spt_values n1,master..spt_values n2
       ) B  on D between date_id_begin and date_id_end

Returns

good_id store_id    promo_name  Date
1122    42          promo_1     2020-02-01
1122    42          promo_1     2020-02-02
1122    42          promo_1     2020-02-03
1122    42          promo_1     2020-02-04
1122    42          promo_1     2020-02-05
2244    41          promo_2     2020-03-01
2244    41          promo_2     2020-03-02
2244    41          promo_2     2020-03-03

如何提取范围内的日期？

How do I extract dates within a range?

sql

tsql

sql-server

date

recursive-query