Hibernate

Java is a backend programming language, hence the developer always has to work with various relational and non-relational database management systems. During the JDBC course, we covered material that allows us to work with relational DBMSs purely in Java Core without connecting additional libraries. But we have seen how difficult and uniform it is to write entity mapping from SQL queries to the database and, vice versa, when we try to save some Java object to the database.

In other words, we do a lot We are engaged in routine work for ORM (Object Relational Mapping).

Moreover, the approach to performing CRUD(Create Read Update Delete) operations for all entities is also uniform.

And one of the most relevant and widely used ORM frameworks in Java - Hibernate.

In this course we will study what an ORM framework is, what the JPA specification is and how Hibernate relates to it.

We will learn all the basic mappings of entities, how relational connections are implemented in the form Java annotations.

What are SessionFactory and Session and how to match them in JDBC.

We will go through the entire life cycle of entities, learn their states and why everything revolves around the PersistenceContext.

We will explore the two levels of caching in Hibernate, and how to solve the N+1 problem!

We will implement our own DAO layer (and how it differs from the Repository layer), which will help us understand the intricacies of how transactions work and why use DTO when working with Hibernate.

On each In this lesson we will go into the source code to understand how everything works from the inside!