Question

我有一个名为Employee的表名。即使任何一个日子都缺失，我也希望得到所有日期。

表：

create table Employee(id int, dateCheck datetime)
insert into Employee values(1, '2016/01/01')
insert into Employee values(2, '2016/01/02')
insert into Employee values(3, '2016/01/05')
insert into Employee values(4, '2016/01/07')

E.g：

+-------------------+--------------------------+
|Name               | dateCheck                |
+-------------------+--------------------------+
| 1                 | 2016-01-01 00:00:00.000  |
| 2                 | 2016-01-02 00:00:00.000  |
| 3                 | 2016-01-05 00:00:00.000  |
| 4                 | 2016-01-07 00:00:00.000  |
+-------------------+--------------------------+

我需要输出如下：

+-------------------+--------------------------+
|Name               | dateCheck                |
+-------------------+--------------------------+
| 1                 | 2016-01-01 00:00:00.000  |
| 2                 | 2016-01-02 00:00:00.000  |
| 0                 | 2016-01-03 00:00:00.000  |
| 0                 | 2016-01-04 00:00:00.000  |
| 3                 | 2016-01-05 00:00:00.000  |
| 0                 | 2016-01-06 00:00:00.000  |
| 4                 | 2016-01-07 00:00:00.000  |
+-------------------+--------------------------+

请帮我解决这个任务。

Answer 1

尝试

;WITH dt (mindt, mxdt) 
     AS (SELECT Min(dateCheck), 
                Max(dateCheck) 
         FROM   Employee 
         UNION ALL 
         SELECT Dateadd(day, 1, mindt), 
                mxdt 
         FROM   dt 
         WHERE  Dateadd(day, 1, mindt) <= mxdt) 
SELECT isnull(em.id,0) as id, 
       dt.mindt 
FROM   dt 
       LEFT JOIN employees em 
              ON mindt = em.dateCheck

Answer 2

点击here查看建议的方法。 Tally表很棒，但是，某些实现不具备性能。拥有物理日期表有时可以提供很大的帮助。

即使SQL Server中也不存在数据，如何获取日期范围内的所有日期？

2 个答案: