sql server - Find Duplicates in SQL and UPDATE them? -

i'm trying find duplicates in table , change 1 of values. use:

select amount bids group amount, auctionid having ( count(amount) > 1 ) ,  (auctionid=1) 

the problem returns

amount 23.6500 41.8800 42.3500 

and not

amount 23.6500 23.6500 41.8800 41.8800 42.3500 42.3500 

so can't update rows.

how can way showed?

thanks, dan

just wrap inside in query:

select amount bids amount in (   select amount   bids   group amount, auctionid   having ( count(amount) > 1 ) ,  (auctionid=1) ) 

update: added update statement

update bids set burned = 1 amount in (   select amount   bids   group amount, auctionid   having ( count(amount) > 1 ) ,  (auctionid=1) )