SELECT column,COUNT(*) c FROM table
GROUP BY column HAVING COUNT(*) > 1

results show the column value and the number of duplicates for that value

DECLARE @order int
SET @order = 1
SELECT * FROM users
ORDER BY 
        CASE WHEN @order = 1 THEN [name] END DESC,
        CASE WHEN @order = 2 THEN [name] END ASC,
        CASE WHEN @order = 3 THEN [email] END DESC,
        CASE WHEN @order = 4 THEN [email] END ASC

set the @order to 1-4 to get specific order by clause, setting it to anything else give results as if no order by clause supplied

remember dynamic SQL (creating SQL in a string and then executing) can not be effectively cached so this is a much better option

SELECT TOP 10 userID
FROM user
ORDER BY NEWID()

or

SELECT TOP 10
        NEWID() [egg],
        userID
FROM user
ORDER BY [egg]

or

SELECT TOP 10
        NEWID(),
        userID
FROM user
ORDER BY 1

only tried the above with TSQL

UPDATE emailFormat 
SET format=2 
FROM emailFormat EF
INNER JOIN user U ON EF.userID = U.userID 

I have seen people use temporay tables and loops to do this sort of thing in the past