I have a parent table and a child table, but no foregin key exsit in database. So there are many records exist in child table but not in parent table. I config many-to-one in child table xml file. When I query data, hibernate2 throws Exception for reporting no key exist in parent table. What is the correct way to descible it in xml?
Exception :
net.sf.hibernate.UnresolvableObjectException: No row with the given identifier exists: 1007009, of class: com.bsteel.newbase.admin.marketdata.model.ProductTypeModel

You said that your data are corrupted (non existing parents referenced by children). You have to clean your DB.

In my system, no distinct foregin key exist in DB. User maybe insert corrupted record via my system. If it happens, system will crash when search these records. But there is many logic foregin key exist, include xxx.hbm.xml. So I check input data when user insert reocrds, I should select many parent tables for one record. System cannot accept the performance and system also have many enterance to insert records(It means I should change many functions to check foregin key).
So I need a simply way to ignore corrupted data when out-join search. Is it prossible now in h2?

No. Hibernate assumes correct relational models.