Introduction to Hibernate (An ORM framework)

ORM overview:

ORM stands for Object Relational Mapping. It is a concept used with Object Oriented Programming language like Java. You can use ORM where two incompatible systems want to share some data with each other. In this tutorial series, we will discuss an ORM named Hibernate.

Limitations in JDBC:

  • The developer should know the SQL for implementing it and make use of it.
  • It depends on Database
  • Migration requires the source code edit.
  • Overhead of Programming involves much
  • Connection management (Open/Close)
  • Manually implement all Create, Read, Update and Delete operations
  • Correct database drivers needed for each database

Introduction to Hibernate:

Hibernate now is much more than just an ORM tool. We can use it in the Data layer in which we want to persist data in the database.

Hibernate implements JPA – Java Persistence API.

java_object_persistence_with_hibernate
Java objects persistence with hibernate

Why Hibernate?

How can you store permanent data in any application? Obviously, in the database. Writing code for making the connection to the databases then writing queries to store data in the form of tables. The query writing requires an effort which means that it needs a complete skill set for SQL query writing. In the case of adding new columns to the database. You must find the code where the logic is implemented and change the code again. Hibernate eliminates this headache by mapping member variable of a class onto the columns of the table present in the database.

SQL queries have many other complexities in them like relationships among tables. There is also need to write the code for maintaining the foreign and primary keys.

As many data types available in programming languages which you can use according to requirements. So, when you need to connect to the database and some incompatibility comes then the problem arises in the form of conversions. Because databases have less number of data types as compared to programming languages, therefore the manual handling of the type conversion is so much hectic.

In object-oriented programming languages, data is stored in various objects. In the case of a change in the object state, the database also needs to be updated.

These are common problems, which are present in any application.  To eliminate these problems you can use Hibernate – ORM tool.

Hibernate VS JDBC

Hibernate JDBC
Hibernate persists object in database JDBC stores primitive types in databases
No need to write Queries for CRUD Need to write Queries for CRUD
Saves objects directly in database Do not Saves objects directly in database
SQL Skill for developer not needed SQL skill for developer needed
No query tuning required in hibernate query tuning required in hibernate
Easy to implement relational databases Not easy to implement relational databases
Can load objects on startup Can’t load objects on startup

Supports automatic versioning

Does not Support automatic versioning

 Hybernate VS JDBC

Advantages Of hibernate:

  • Maps Java class to the database with minimal effort
  • API is simple and easy to understand
  • We can change full database by just manipulating configuration file of hibernate
  • No application server is needed to operate.
  • Faster database access
  • Can generate primary key
  • Productivity, Portability, and the maintainability are the core benefits
  • Free of cost – affordable
  • Easy to Learn

Technical Benefits of Hibernate

  • The database does not depend on Hibernate; both work independently.
  • Based on standard ORM principles
  • Provides JPA abilities
  • C3P0 is built-in in hibernate; C3P0 is the connection pool implementation
  • Implemented on Layered Architecture
  • HQL-Hibernate Query Language provides pagination and dynamic profiling
  • OOP’s concept implemented using HQL
  • Cache support increases its performance
  • Lazy loading also increases its performance

Summary:

Hibernate is an ORM tool for connecting the application with database. It is a free, fast and simple tool which eliminates the need of SQL along with effectively good performance results.

In this tutorial, we have accomplished following things.

  • Overview of the ORM
  • Limitations of JDBC
  • Introduction to Hibernate
  • Why Hibernate?
  • Hibernate VS JDBC
  • Advantages Of hibernate
  • Technical Benefits of Hibernate

Hope that you like this tutorial. Stay tuned for more upcoming tutorials. Stay Blessed!

About Author: Uzair Ahmed Khan is Technical Content Writer, Computer Software Blogger, and Software Engineer. He has a keen eye on Java Technologies other Related Developments.