query assistance

Is there a straight forward way to pull out duplicates in a particular
field given a value in another field?
For example, I have a table that lists users and study names associated
with those users. Each user can have one or more study names. My goal is
to determine if any of these people have duplicate study names. There
are duplicated study names across the system and that is ok. I just want
to see if any users have duplicate study names among their studies.
My table looks like this:

Table "public.study"
Column | Type |
Modifiers
--------------+-----------------------------+------------------------------------------
sty_pk | integer | not null default
nextval('pk_seq'::text)
study_name | character varying(128) | not null
start_date | timestamp without time zone |
sty_comments | text |
created_by | integer |
Indexes: study_pkey primary key btree (sty_pk)

I am concerened with study_name. The created_by field tells me who owns it.
Thanks
Jodi

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/_______________________________
//Jodi L Kanter
BioInformatics Database Administrator
University of Virginia
(434) 924-2846
jkanter(at)virginia(dot)edu <mailto:jkanter(at)virginia(dot)edu>/

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