SQL Server pivot with "ties" - sql

Question

Here is my source data:
+-------+-------+-------+------+
| Categ | Nm | Value | Rnk |
+-------+-------+-------+------+
| A | Tom | 37 | 1 |
| A | Joe | 36 | 2 |
| A | Eddie | 35 | 3 |
| B | Seth | 28 | 1 |
| B | Ed | 25 | 2 |
| B | Billy | 22 | 3 |
| C | Julie | 42 | 1 |
| C | Jenny | 41 | 2 |
| C | April | 40 | 3 |
| C | Mary | 40 | 3 |
| C | Laura | 40 | 3 |
+-------+-------+-------+------+
And here is the output I would like to produce:
+------+--------+--------+-------+
| Rnk | A | B | C |
+------+--------+--------+-------+
| 1 | Tom | Seth | Julie |
| 2 | Joe | Ed | Jenny |
| 3 | Eddie | Billy | April |
| 3 | (null) | (null) | Mary |
| 3 | (null) | (null) | Laura |
+------+--------+--------+-------+
I have used the following approach (which I understand through other posts may be superior to actually using PIVOT)...and this gets me to where I see Julie/Jenny/April, but not Mary/Laura (obviously, since it is pulling the MIN in the event of a 'tie').
SELECT Rnk
, min(CASE WHEN Categ = 'A' THEN Nm END) as A
, min(CASE WHEN Categ = 'B' THEN Nm END) as B
, min(CASE WHEN Categ = 'C' THEN Nm END) as C
FROM Tbl
GROUP BY Rnk
How to get to my desired output?

Answer 1

Well, if you want multiple rows for each rank, you can't aggregate by rank, or at least by rank alone. So, calculate the rank-within-the-rank or as the following query calls it, the sub_rnk:
SELECT Rnk,
min(CASE WHEN Categ = 'A' THEN Nm END) as A,
min(CASE WHEN Categ = 'B' THEN Nm END) as B,
min(CASE WHEN Categ = 'C' THEN Nm END) as C
FROM (select t.*, row_number() over (partition by categ, rnk order by newid()) as sub_rnk
from Tbl t
) t
GROUP BY rnk, sub_rnk
ORDER BY rnk;