日期时间值生成 MS SQL答案

【问题标题】：Datetime values generation MS SQL日期时间值生成 MS SQL
【发布时间】：2020-11-06 14:59:20
【问题描述】：

有两个可用的 DateTime 值变量：例如，@STARTDATETIME = '2020-10-21 14:45' 和 @ENDDATETIME = '2020-10-22 19:00'

如果 STARTDATETIME = '2020-10-21 12:00' 和 ENDDATETIME = '2020-10-21 16:00' 这样的日期之间只有一天，则变量必须保存初始值。

如果两个值之间有一天或多天，则第一个日期必须从给定的时间戳开始到 16:00。所有中间天的时间必须是从 08:00 到 16:00。最后一天必须从 08:00 时间开始，直到给定的时间戳。

完整示例：

@STARTDATETIME = '2020-10-21 14:45' and @ENDDATETIME = '2020-10-23 19:15'

期望的输出（表格）：

STARTDATETIME      | ENDDATETIME 
'2020-10-21 14:45' | '2020-10-21 16:00'
'2020-10-22 08:00' | '2020-10-22 16:00'
'2020-10-23 08:00' | '2020-10-23 19:15'

【问题讨论】：

标签： sql sql-server datetime range

【解决方案1】：

您可以使用递归 CTE：

with dates as (
      select @STARTDATETIME as startdt,
             (case when datediff(day, @STARTDATETIME, @ENDDATETIME) = 0
                   then @ENDDATETIME
                   else dateadd(day, 1, convert(date, @STARTDATETIME))
              end) as enddt
      union all
      select enddte,
             (case when datediff(day, enddte, @ENDDATETIME) = 0
                   then @ENDDATETIME
                   else dateadd(day, 1, convert(date, enddte))
              end) as enddt,
             @ENDDATETIME as enddatetime
      from dates
      where enddt < @enddatetime
     )
select *
from date;

【讨论】：

【解决方案2】：

这个会每天给你一排：


    DECLARE @start dateTime = '20201021 14:45:00'
    DECLARE @end dateTime = '20201023 19:15:00'
    DECLARE @startDate Date = CAST(@start as date)
    DECLARE @endDate Date = CAST(@end as date)
    DECLARE @startTime Time = CAST(@start as time)
    DECLARE @endTime Time = CAST(@end as time)
    DECLARE @startOfDay DateTime = '08:00:00'
    DECLARE @endOfDay DateTime = '16:00:00';
    
    
    WITH lv0 AS (SELECT 0 g UNION ALL SELECT 0)
        ,lv1 AS (SELECT 0 g FROM lv0 a CROSS JOIN lv0 b) -- 4
        ,lv2 AS (SELECT 0 g FROM lv1 a CROSS JOIN lv1 b) -- 16
        ,lv3 AS (SELECT 0 g FROM lv2 a CROSS JOIN lv2 b) -- 256
        ,lv4 AS (SELECT 0 g FROM lv3 a CROSS JOIN lv3 b) -- 65,536
        ,lv5 AS (SELECT 0 g FROM lv4 a CROSS JOIN lv4 b) -- 4,294,967,296
        ,Tally (n) AS (SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM lv5)
    ,
    dates AS
    (
    SELECT 
      DateAdd(day,n-1,@startDate) as [Day]
    FROM tally
    WHERE n<=DATEDIFF(day,@startDate,@endDate)+1
    )
    select 
      [Day],
      CASE WHEN [Day]=@startDate THEN @start ELSE CAST([DAY] AS DateTime)+@startOfDay END as [startOfWork],
      CASE WHEN [Day]=@endDate THEN @end ELSE CAST([DAY] AS DateTime)+@endOfDay END as [endOfWork]
    
    FROM dates

结果：

| Day        | startOfWork             | endOfWork               |
|------------|-------------------------|-------------------------|
| 2020-10-21 | 2020-10-21 14:45:00.000 | 2020-10-21 16:00:00.000 |
| 2020-10-22 | 2020-10-22 08:00:00.000 | 2020-10-22 16:00:00.000 |
| 2020-10-23 | 2020-10-23 08:00:00.000 | 2020-10-23 19:15:00.000 |

【讨论】：