ordering query results with two columns

Question

I have this table:

Reply_ID | Fk_Post_ID
   10    |    5
   9     |    6
   8     |    5
   7     |    9
   6     |    5
   5     |    9
   4     |    7

I need a query retrieves records in the following order pattern. it searches for the record with the highest reply_ID then retrieves all records having the same Fk_Post_ID. something like this:

Reply_ID | Fk_Post_ID
   10    |    5
   8     |    5
   6     |    5
   9     |    6
   7     |    9
   5     |    9
   4     |    7

Answer 1

CREATE TABLE #YourTable (
    Reply_ID INT,
    fk_Post_ID INT
)

INSERT INTO #YourTable VALUES (10, 5)
INSERT INTO #YourTable VALUES (9, 6)
INSERT INTO #YourTable VALUES (8, 5)
INSERT INTO #YourTable VALUES (7, 9)
INSERT INTO #YourTable VALUES (6, 5)


SELECT
    t1.Reply_ID, 
    t1.fk_Post_ID
FROM
    #YourTable t1 JOIN (
    SELECT 
        MAX(Reply_ID) AS Max_Reply_ID,
        fk_Post_ID
    FROM #YourTable
    GROUP BY fk_Post_ID
) t2 ON t2.fk_Post_ID = t1.fk_Post_ID
ORDER BY 
    t2.Max_Reply_ID DESC, 
    t1.Reply_ID DESC

Sql Fiddle Here