This is a general question about the inner workings of Hibernate.
Suppose I have 3 tables: Countries, Provinces and Municipalities.
Each one has a one-to-many relationship to the next one.
All data is normalized, there are no orphan records anywhere.

In order to build a criteria, I use the following code.



The previous code works only if restrictions apply to the main class (Country), but if a restriction apply to one of the child tables, say, Municipality, when the values are retrieved a LazyInitializationException is thrown.


The following code solves the problem:



Could anyone explain to me why a LEFT JOIN is necessary, when all the data is normalized?

Thanks in advance

Gonzalo Díaz

I withdraw this question.
There is nothing inherent to the Criteria that forces a LEFT JOIN on the children.
My problem was that, along with the children (Provinces) of "Countries", I had several other one-to-many associations issuing from the main table.
This caused nulls to be returned on the right side of my resultset.
The only way a consistent resultset can be returned in this case, is by using LEFT JOINS all the way.

Gonzalo Díaz