Hibernate is a free and open source ORM tool specially designed for Java which helps to map objects to an RDBMS and to execute those object-oriented programmed ideas in a relational database. JDBC (Java Database Connectivity) is another free and open source programming interface for Java which helps developers create a query and update data using SQL to a relational database. This interface gives the applications an access to other databases.
If you have felt irritated overwriting the same code again and again on Java, or you are struggling for a long time to map objects to your database table, then it is the best option to switch over to Hibernate. Hibernate will also give you the facility to implement OOPS with your code and will give you an easy access to migrate from one database to another comfortably.
If you want to learn Hibernate, you will have to face a few questions in the interview. Therefore, some of the relevant hibernate interview questions are stated below which you should know before you appear for the interview.
The ORM or object-relational mapping is a programming tool which is used to map those objects that are present in the database. It will help you to create, access and manipulate objects in a simpler way.
The entire framework of Hibernate use core interfaces like Session Factory, Query, Criteria, Session, Transaction and Configuration.
The objects of Hibernate can exist in 3 states:a) Transient: Here, you can create the object but there is no primary key or identifier. Neither are the objects associated with any session.
b) Persistent: In this the object session is open and you can save and retrieve information from the database.c) Detached: This state is when the object session gets closed but the objects have not been called yet.
The strategies used for inheritance mapping includes tables per class, tables per hierarchy and tables per subclass.
This file has configurations which are exclusive to the database. This is the first object which you can create and it comprises the properties file that is required by an application. Usually, this file is created only once.
Lazy loading is the process where the objects are loaded only when it is demanded. It improves the overall functioning of the program by loading only the child objects when it is asked for.
A configuration interface bootstraps hibernate. It is used only when hibernating session functions by mapping documents.
The query language used in Hibernate is called HQL (Hibernate Query Language). It is a simpler and efficient extension of SQL. It is more flexible and can perform multiple functions on a database.
These are the important questions which you need to know before you apply for a certified course on Hibernate.