Fetch single row if two columns in table have same values either ways

sql, sql-server

Solution

SELECT CASE
         WHEN caller < callee THEN callee
         ELSE caller
       END      AS caller1,
       CASE
         WHEN caller < callee THEN caller
         ELSE callee
       END      AS caller2,
       Count(*) AS [Count]
FROM   YourTable
GROUP  BY CASE
            WHEN caller < callee THEN callee
            ELSE caller
          END,
          CASE
            WHEN caller < callee THEN caller
            ELSE callee
          END

Problem

I have a table with columns caller and callee with following values say ``` caller callee 999 888 888 999 999 555 555 333 555 999 ``` now i want only single row in returned as ``` caller1 caller2 count 999 888 2 999 555 1 555 333 1 555 999 2 ```

Original source