Find duplicate query

[barry.marcus]

If I have a simple table with the following structure

id counter
WKU varchar

What query will show me the WKUs that are duplicated? For example, assume I have the following WKU data:

WKU
---
AAAA
BBBB
BBBB
BBBB
CCCC
DDDD
DDDD
EEEE

What query will display the following result, since 'BBBB' and 'DDDD' are duplicated in the table:

WKU
---
BBBB
DDDD

Thanks in advance for your help.

[John]

You can do the following:

select WKU, count(*) N from T group by WKU having N > 1;

which will also display the count for the duplicated fields, e.g.

WKU N
-------------
BBBB 3
DDDD 2

[barry.marcus]

Thank you. That's what I need.