How find dublicate?

pls tell me answer for a Oracle interview questionHow to find dublicate value's number of occurence?with out using for loop.
[146 byte] By [hai_karuppaIyana] at [2007-11-26 20:25:36]
# 1
http://www.oracle.com/support/index.html
rukbata at 2007-7-10 0:52:30 > top of Java-index,Desktop,Runtime Environment...