Crucial Hibernate Interview Questions
Q1: What do you mean by Hibernate?
Ans: One of the famous frameworks that makes the development of Java applications easy is Hibernate. This Java framework helps in the interaction of the applications with the database. For the reference implementation of Java API, this Object-relational mapping (ORM) can be used.
It comprises an abstraction layer. Moreover, it takes care of the internal implementations. These implementations are tasks, such as typing a query for CRUD operations. And, it forms a link with the databases, etc.
Hibernate saves the data in the storage and processes the data for long term usage by developing persistence logic. Hibernate is not a heavyweight tool. The biggest advantage of using hibernate over other frameworks is that it is an open-source tool.
Q2: Why is Hibernate better than JDBC?
Ans:There are some benefits that Hibernate has overJDBC. They are given below:
- Hibernate removes many boiler-plate code that are present in the JDBC API. Hence, the code is clean with better readability.
- JDBC doesn’t support features like associations, inheritance, and collections. These features are available in Hibernate.
- The Hibernate Query Language somewhat resembles Java. And, it is more object-oriented. Whereas, when you use JDBC, you must write the native SQL queries.
- Hibernate indirectly allows transaction management. However, you need to use commit and rollback to write code for transaction management in JDBC.
- Similarly, JDBC throws a checked exceptionSQLException. Due to that, you are required to write try-catch block code. Hibernate encloses the JDBC exceptions and throws exceptions that are unchecked. As a result, there is no need for you to write a code to handle. With it’s built-in transaction management, it aids in eliminating the usage of try-catch blocks.
Q3: Why do you need to use the Hibernate Framework?
Ans: Actually, Hibernate has many features that other technologies like JDBC lack. That is why you can use this tool for a number of operations. We have written the key advantages of hibernate below:
- It deals with the database dependency that is experienced in the other technologies.
- Usually, when you need to change the databases, it requires an extensive amount of work. Hibernate has solved this issue without difficulty.
- While working with some other frameworks, code portability is not an option. Nevertheless, hibernate knows how to manage that.
- Hibernate provides strength to the object level relationship.
- With Hibernate, you no longer have to worry about the exception-handling part. In JDBC, it is a necessary component.
- As it lessens the length of code, it becomes more readable. The boilerplate problem is solved as well.
Q4: What type of functionalities are supported by Hibernate?
Ans: We have mentioned this earlier too that Hibernate is an ORM tool. That is one of the reasons why it supports the functionalities that are important for the developers.
- Hibernate has Hibernate Query Language(HQL). It is an object-oriented query language that is almost identical to SQL. Unlike SQL, it doesn’t work on tables and columns. Instead of that, it operates completely with persistent objects. It translates the HQL queries into conventional SQL queries. So, it doesn’t rely on the database.
- You can perform auto DDL operations with it.
- You will also find Auto Primary Key Generation support.
- It has cache memory support.
- Exception handling is a necessary part of this framework.
Q5: What is the One-to-One association in Hibernate?
Ans:In actuality, a one-to-one association is like a many-to-one association. But, here, the column is to be set as unique. In a one-to-one kind of mapping, you must represent the system in a way that it exists independently. For that, in the query or domain model, you have to navigate the relationship.
This is the entity attribute that is responsible for the association. Hence, work with @OneToOne annotation by annotating it. To fully understand how this association works, you have to work with hibernate. Once you begin to work with a hibernate application, then you will learn about the one-to-one relationships between multiple entities.