SQL Renaming NULL for null values and rollup - sql

Question

I'm trying to make a dashboard to show open tickets and who they are assigned to, by priority. The data set looks like:
|-------------------------|
| Assigned | Priority |
|-------------------------|
| JOE | Low |
| JOE | Medium |
| MARY | High |
| | Medium |
| TIM | Low |
| Mary | High |
The report I'm trying to get is:
|---------------------------------------------------------|
| 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 |
I can get it all, with this query
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
This way however, it is renaming anything that was NULL to Unassigned. This is perfect to give me the Unassigned values that don't have anyone in the Assigned field, however my Total column is also showing Unassigned. How do I rename that to Total?
Thanks in advance!

Answer 1

You need to use GROUPING, like this:
SQL Fiddle
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
Results:
| 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 |