Book Image

Java Hibernate Cookbook

By : Yogesh Prajapati, Vishal Ranapariya
Book Image

Java Hibernate Cookbook

By: Yogesh Prajapati, Vishal Ranapariya

Overview of this book

This book will provide a useful hands-on guide to Hibernate to accomplish the development of a real-time Hibernate application. We will start with the basics of Hibernate, which include setting up Hibernate – the pre-requisites and multiple ways of configuring Hibernate using Java. We will then dive deep into the fundamentals of Hibernate such as SessionFactory, session, criteria, working with objects and criteria. This will help a developer have a better understanding of how Hibernate works and what needs to be done to run a Hibernate application. Moving on, we will learn how to work with annotations, associations and collections. In the final chapters, we will see explore querying, advanced Hibernate concepts and integration with other frameworks.
Table of Contents (15 chapters)
Java Hibernate Cookbook
About the Authors
About the Reviewers

Executing a query using HQL

HQL stands for Hibernate Query Language and is a fully object-oriented language. This language is a bit similar to the native query, but in the native SQL query, we use the physical table name and actual physical columns to execute a query, and in HQL, we have to use a class name instead of a table name and a field name instead of a column name.

HQL queries are converted to SQL queries by hibernate; so, we can use any of the styles. However, HQL is preferable from a performance point of view, because hibernate uses SQL directly without any optimization, and the HQL query uses hibernate's query generation strategy and caching mechanism.

How to do it…

There are multiple clauses available to work with HQL.

The FROM clause

We will use the simple FROM clause to query an object to load the complete object.

Here, we will use the FROM Category query, which is equal to SELECT * FROM category in native SQL. Execute the following code:

Query query = session.createQuery("FROM...