In this site there are many tutorials and example of HQL. These examples comes with HQL sample code that you can download and run on your computer and learn the HQL by modifying and executing these examples.
The HQL Sample code is written in easy to understand manner. You will be able to understand technical stuff very easily.
The HQL or Hibernate Query language is very powerful and can be easily used to develop complex query in Java program. HQL is then translated into SQL by the ORM component of Hibernate.
HQL is very powerful and it supports following advanced features:
With the help of HQL you can do the following things: