What is ORM in Java?

In the world of software development, Object-Relational Mapping (ORM) frameworks have become a crucial tool for developers to work with databases. ORM is a technique that maps the database tables to objects in programming languages, making it possible to manipulate data using object-oriented programming principles. ORM frameworks automate the process of mapping, querying, and managing data between the database and the application, allowing developers to focus on business logic rather than the technical details of database management.

What is unidirectional and bidirectional relationship?

In the world of database design, relationships play a crucial role in organizing data and ensuring smooth data retrieval. There are two types of relationships between tables: unidirectional and bidirectional. Understanding the differences between the two is essential for creating an efficient database design that meets the needs of its users. A unidirectional relationship is a one-way connection between two tables. In this type of relationship, one table, called the primary table, is linked to another table, called the secondary table, through a foreign key. The primary table is the owner of the relationship, and the secondary table is dependent on the primary table. The inverse is not true; the primary table does not depend on the secondary table. This type of relationship is useful when data needs to be accessed from the primary table alone, without the need for secondary data.