Order by decimals for counts of same value - sql

Question

EDIT: I have edited this question to make the query simpler:
ReportTracking:
Userid, ReportId, Duration, CreatedDate
Query:
SELECT t.UserId, COUNT(DISTINCT(t.ReportId)) AS ReportsRead
FROM ReportTracking t
WHERE t.Duration >= 30
AND t.CreatedDate > DATEADD(Day, -30, GETDATE())
GROUP BY t.UserId
Sample Result:
UserId ReportsRead
1 22
2 13
3 2
4 2
5 2
What I need to do is assign a number value to Reports Read. Essentially because there are 3 users who read swimming and they tie in terms of ranking (they each have 2 read only) I need to order them by who read the report last. I need to assign them all a decimal number value based on order of reading. So the person who read the report last would get .1, the person who read it first would get .3.
I'm not quite sure how to achieve this, the key part is that they do have have a decimal number value that ranks them and this decimal should be few decimal points long as the records are rather long. My idea was to use DateCreated and convert it a number value which I can substract from a max. But since there are multiple dates (one for each report), I'm not sure how to grab the latest one and only use that date with my report count.

Answer 1

I'm not sure why you need to assign decimals...
Just order by ReportsRead desc, max(createdDate) (this should be most recent read for a user in the select).
Also distinct isn't a function it's a statement. No need for the ()
SELECT t.UserId
, COUNT(DISTINCT t.ReportId) AS ReportsRead
max(t.createDate) Asc) RN
FROM ReportTracking t
WHERE t.Duration >= 30
AND t.CreatedDate > DATEADD(Day, -30, GETDATE())
GROUP BY t.UserId
ORDER BY ReportsRead DESC, max(createdDate)
if you need the numbers and plan on displaying them
WITH CTE AS (
SELECT t.UserId
, COUNT(DISTINCT t.ReportId) AS ReportsRead
, row_number() over (partition by count(Distinct t.reportID) order by max(t.createDate) Asc) RN
FROM ReportTracking t
WHERE t.Duration >= 30
AND t.CreatedDate > DATEADD(Day, -30, GETDATE())
GROUP BY t.UserId)
SELECT *
FROM CTE
ORDER BY ReportsRead DESC, RN

Answer 2

You can rank your rows within ReportsRead partition to obtain a ranking by ordering on the max(createddate). documentation: SQL Server Rank function
here is an example: http://sqlfiddle.com/#!18/1eefc/11
You may simplify the query by using CTE to reuse column aliases but the concept is:
SELECT t.UserId
, COUNT(DISTINCT( t.ReportId )) AS ReportsRead
, CAST(RANK()
OVER(
partition BY COUNT(DISTINCT( t.ReportId ))
ORDER BY MAX(t.createdDate) DESC) AS DECIMAL) / 10 ranking
FROM ReportTracking t
WHERE t.Duration >= 30
AND t.CreatedDate > DATEADD(Day, -30, GETDATE())
GROUP BY t.UserId
ORDER BY ReportsRead DESC
, ranking;