Hibernate: HQL in Depth - Points to Remember (Page 4 of 4 )
There are some points to be kept in mind when working with HQL. They are as follows:
1. Queries are case insensitive, barring the Java class and propertiesí names. Hence SELECT and select are the same, but Order and order are not.
2. If the class or package does not find a place in imports, then the objects have to be called with the package name. For example, if com.someorg.persist.Order is not imported, then the query would be from com.someorg.persist.Order and so on.
3. A query like
from Foo foo where foo.bar.baz.customer.address.city is not null
would translate into a SQL query with four joins. So such queries should be used when absolutely necessary, as joins cost heavily in terms of memory and processing.
Thatís all for this discussion. In the future I would be covering Criteria queries and advanced HQL. Till then.
DISCLAIMER: The content provided in this article is not warranted or guaranteed by Developer Shed, Inc. The content provided is intended for entertainment and/or educational purposes in order to introduce to the reader key ideas, concepts, and/or product reviews. As such it is incumbent upon the reader to employ real-world tactics for security and implementation of best practices. We are not liable for any negative consequences that may result from implementing any information covered in our articles or tutorials. If this is a hardware review, it is not recommended to open and/or modify your hardware.