SQL 为空值和汇总重命名 NULL

Question

我正在尝试制作一个仪表板来显示未处理的票证以及它们被分配给谁的优先级。数据集如下所示：

|-------------------------|
|  Assigned  |  Priority  |
|-------------------------|
|  JOE       |  Low       |
|  JOE       |  Medium    |
|  MARY      |  High      |
|            |  Medium    |
|  TIM       |  Low       |
|  Mary      |  High      |

我想得到的报告是：

|---------------------------------------------------------|
|  Employee  |  Low   |   Medium   |   High   |   Total   |
|---------------------------------------------------------|
| Total      |   2    |     2      |    2     |     6     |
| Unassigned |   0    |     1      |    0     |     1     |
|  MARY      |   0    |     0      |    2     |     2     |
|  JOE       |   1    |     1      |    0     |     2     |
|  TIM       |   1    |     0      |    0     |     1     |

我可以得到这一切，通过这个查询

SELECT
    CASE WHEN Assigned is null then 'Unassigned' Else Assigned End Employee
    ,   SUM(CASE WHEN Priority = 'Low' THEN 1 ELSE 0 END) AS Low
    ,   SUM(CASE WHEN Priority = 'Medium' THEN 1 ELSE 0 END) AS Medium
    ,   SUM(CASE WHEN Priority = 'High' THEN 1 ELSE 0 END) AS High
    ,   count(Priority) AS Total
FROM table
GROUP BY Assigned WITH ROLLUP
ORDER BY Assigned ASC

但是，通过这种方式，它将任何为 NULL 的内容重命名为未分配。这非常适合为我提供在已分配字段中没有任何人的未分配值，但是我的总计列也显示未分配。我如何将其重命名为 Total？

提前致谢！

Answer 1

您需要使用GROUPING，如下所示：

SQL小提琴

SELECT
    CASE WHEN (GROUPING(Assigned) = 1) THEN 'Total'
        When Assigned is null then 'Unassigned' 
        Else Assigned End Employee
    ,   SUM(CASE WHEN Priority = 'Low' THEN 1 ELSE 0 END) AS Low
    ,   SUM(CASE WHEN Priority = 'Medium' THEN 1 ELSE 0 END) AS Medium
    ,   SUM(CASE WHEN Priority = 'High' THEN 1 ELSE 0 END) AS High
    ,   count(Priority) AS Total
FROM table1
GROUP BY Assigned WITH ROLLUP
--DER BY Assigned ASC

结果：

|   EMPLOYEE | LOW | MEDIUM | HIGH | TOTAL |
|------------|-----|--------|------|-------|
| Unassigned |   0 |      1 |    0 |     1 |
|        JOE |   1 |      1 |    0 |     2 |
|       MARY |   0 |      0 |    2 |     2 |
|        TIM |   1 |      0 |    0 |     1 |
|      Total |   2 |      2 |    2 |     6 |