Hi all,
I'm having problems creating relationship mappings. Ok, I have 3 tables:
Table1: t1_id:PK (primary key) and some other fields

Table2: t2_id:PK (primary key) and some other fields

Table3: t1_id:FK (foreign key) references Table1
t2_id:FK (foreign key) references Table2
... and some fields

relationship of Table1 to Table3 is one to many / many to one
" " Table2 to Table3 is one to one

How should I define my xml mappings? Please help.... Thanks in advance!

I suggest you read the online documents then possibly invest in HIA book.
After you have read the basics (and tried a few things). This (which is a part of the docs) will answer your relationship questions.
http://www.hibernate.org/hib_docs/reference/en/html/example-parentchild.html