Always fetch 3 records in a particular order

I have a query which gets 3 books (ABC1,ABC2,ABC3) and their details. I need them in a particular order for pivoting so I have a Row number column for the same. People read none/some/all books.

Table:

StudentID|||BookName|||RowNumber
1000|||ABC1|||27
1000|||ABC2|||31
1000|||ABC3|||28
1005|||ABC2|||28
1005|||ABC3|||20
1005|||ABC1|||25
1006|||ABC1|||12
1006|||ABC2|||14
1006|||ABC3|||15

So my data would be something like the above. I need for each student, ABC1,ABC2,ABC3 should come in the order AND Rownumber to be UPDATED in descending order. So for student 1000:

ABC1||27,ABC2||28,ABC3||31

For student 1005:

ABC1||20,ABC2||25,ABC3||28

For 1006: no change (they're already in the right order).

I have all the above data into a temp table and master data into another temp table. I'm trying to write an update statement but nothing works as expected. I need some help.

CREATE TABLE #t(StudentID INT, BookName VARCHAR(10), RowNumber INT);

INSERT #t(StudentID,BookName,RowNumber) VALUES
(1000,'ABC1',27),    (1000,'ABC2',31),    (1000,'ABC3',28),
(1005,'ABC2',28),    (1005,'ABC3',20),    (1005,'ABC1',25),
(1006,'ABC1',12),    (1006,'ABC2',14),    (1006,'ABC3',15);

;WITH x AS 
(
  SELECT StudentID, BookName, RowNumber, 
   rn1 = ROW_NUMBER() OVER (PARTITION BY StudentID ORDER BY BookName),
   rn2 = ROW_NUMBER() OVER (PARTITION BY StudentID ORDER BY RowNumber)
  FROM #t
)
SELECT x.StudentID, x.BookName, y.RowNumber
 FROM x INNER JOIN x AS y
  ON x.StudentID = y.StudentID
  AND x.rn1 = y.rn2
ORDER BY x.StudentID, x.rn1;
GO

DROP TABLE #t;

Results:

StudentID BookName RowNumber
--------- -------- ---------
1000 ABC1 27
1000 ABC2 28
1000 ABC3 31
1005 ABC1 20
1005 ABC2 25
1005 ABC3 28
1006 ABC1 12
1006 ABC2 14
1006 ABC3 15


StackExchange Database Administrators Q#116053, answer score: 7