分解跨天的时间数据

/*测试数据*/
WITH    x0
          AS ( SELECT   ‘A‘ AS sb ,
                        CONVERT(DATETIME, ‘2015-08-01 17:06:49‘) AS date_begin ,
                        CONVERT(DATETIME, ‘2015-08-02 03:41:32‘) AS date_end ,
                        635 AS total_time
               UNION ALL
               SELECT   ‘B‘ AS sb ,
                        CONVERT(DATETIME, ‘2015-08-01 20:54:42‘) AS date_begin ,
                        CONVERT(DATETIME, ‘2015-08-03 23:50:52‘) AS date_end ,
                        3056 AS total_time
               UNION ALL
               SELECT   ‘C‘ AS sb ,
                        CONVERT(DATETIME, ‘2015-08-04 12:40:20‘) AS date_begin ,
                        CONVERT(DATETIME, ‘2015-08-05 23:59:59‘) AS date_end ,
                        2119 AS total_time
             ),/*计算两个时间点之间相差的天数*/
        x1
          AS ( SELECT   sb ,
                        date_begin ,
                        date_end ,
                        total_time ,
                        DATEDIFF(day, date_begin, date_end) AS cacl_day--开始时间和结束时间相差的天数
               FROM     x0
             ),/*将隔天的时间分解*/
        x2
          AS ( SELECT   sb ,
                        CASE WHEN msv.number = 0 THEN date_begin
                             ELSE CONVERT(VARCHAR(10), DATEADD(DAY, msv.number,
                                                              date_begin), 120)
                        END AS date_begin ,
                        CASE WHEN msv.number = x.cacl_day THEN date_end
                             ELSE CONVERT(VARCHAR(10), DATEADD(DAY, msv.number,
                                                              date_begin), 120)
                                  + ‘ 23:59:59‘
                        END AS date_end ,
                        total_time ,
                        CASE WHEN msv.number = x.cacl_day THEN 1
                             ELSE 0
                        END AS flag--如果是最后一天，标识为1，否则为0
               FROM     x1 x ,
                        master..spt_values msv
               WHERE    msv.type = ‘P‘
                        AND msv.number <= x.cacl_day
             ),
        x3
          AS ( SELECT   sb ,
                        date_begin ,
                        date_end ,
                        total_time ,
                        CASE WHEN CONVERT(CHAR(8), date_begin, 108) = ‘00:00:00‘
                                  AND CONVERT(CHAR(8), date_end, 108) = ‘23:59:59‘
                             THEN 1440
                             ELSE DATEDIFF(MINUTE, date_begin, date_end)
                        END AS cacl_time ,--如果是一整天，那么是1440分钟，否则，2个时间相减
                        flag ,
                        ROW_NUMBER() OVER ( PARTITION BY sb ORDER BY date_end ) AS rn--行号，用于后面统计各天的剩余分钟
               FROM     x2
             )
    SELECT  sb ,
            date_begin ,
            date_end ,
            CASE WHEN flag = 1 THEN total_time - ( SELECT   SUM(cacl_time)
                                                   FROM     x3 x
                                                   WHERE    x.sb = x3.sb
                                                            AND x.rn < x3.rn
                                                 )
                 ELSE cacl_time--最后一天的耗时是总时间减去前面的时间总和
            END AS cacl_time
    FROM    x3