DB with Spring boot

*Configuration for connecting db to springboot application

-need to configure application.yml file

inside application file need to provide data for few fields

1) spring.datasource.url

2) spring.datasource.username

3) spring.datasource.password

4) spring.datasource.driver-class-name

JPA (Java Persistence API)

Requirements: application should be running above java 8+

Annotation which helps jpa to understand about fields:?

Model layer

@Entity: This annotation defines that a class can be mapped to a table

@Id: This annotation specifies the primary key of the entity.

@GeneratedValue: This annotation is used to specify the primary key generation strategy to use. i.e. Instructs database to generate a value for this field automatically. If the strategy is not specified by default AUTO will be used.

Repository layer

@Repository

Important annotation

@Transient: Tells the hibernate, not to add this particular column

What is JPA?

A JPA (Java Persistence API) is a specification of Java which is used to access, manage, and persist data between Java object and relational database. It is considered as a standard approach for Object Relational Mapping.

JPA can be seen as a bridge between object-oriented domain models and relational database systems. Being a specification, JPA doesn't perform any operation by itself. Thus, it requires implementation. So, ORM tools like Hibernate, TopLink, and iBatis implements JPA specifications for data persistence.

What is Hibernate?

A Hibernate is a Java framework which is used to store the Java objects in the relational database system. It is an open-source, lightweight, ORM (Object Relational Mapping) tool.

Hibernate is an implementation of JPA. So, it follows the common standards provided by the JPA.