显示两个日期与数据之间的所有日期

Question

我从这个论坛得到了以下代码。它从员工出勤中检索数据，如：

   userid dateandtime checktype 
1. 100    01/01/2015  I
2. 100    01/01/2015  O
3. 102    02/02/2015  I
4. 102    02/02/2015  O

现在我想检索两个特定日期之间的所有数据，但是即使缺少一个日期也应检索所有日期，这些日子应该在小时栏中显示空白或零

SELECT  t.UserID ,
        [Date] = DATEADD(dd, 0, DATEDIFF(dd, 0, t.CheckIn)) ,
        CheckIn = CONVERT(VARCHAR(10), t.CheckIn, 108) ,
        CheckOut = CONVERT(VARCHAR(10), t.CheckOut, 108) ,
        [Hours] = CAST(DATEDIFF(MINUTE, t.CheckIn, t.CheckOut) / 60. AS DECIMAL(10,
                                                              2))
FROM    ( SELECT    t.UserID ,
                    CheckIn = t.Checktime ,
                    CheckOut = r.Checktime ,
                    RowNum = ROW_NUMBER() OVER ( PARTITION BY t.UserID,
                                                 r.Checktime ORDER BY 1 / 0 )
          FROM      CHECKINOUT t
                    OUTER APPLY ( SELECT TOP 1
                                            *
                                  FROM      CHECKINOUT t2
                                  WHERE     t2.UserID = t.UserID
                                            AND t2.Checktime > t.Checktime
                                            AND DATEADD(dd, 0,
                                                        DATEDIFF(dd, 0,
                                                              t.Checktime)) = DATEADD(dd,
                                                              0,
                                                              DATEDIFF(dd, 0,
                                                              t2.Checktime))
                                            AND t2.Checktype = 'O'
                                  ORDER BY  t2.Checktime
                                ) r
          WHERE     t.Checktype = 'I'
        ) t
WHERE   t.RowNum = 1