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Explanation

To connect a Spring Boot REST API to a MySQL database, first configure the database connection properties in the application.properties file. Spring Boot uses these settings to establish a connection with MySQL.

Code:

spring.datasource.url=jdbc:mysql://
localhost:3306/studentdb
spring.datasource.username=root
spring.datasource.password=root
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true

Explanation

Create an Entity class to map a Java object to a database table. The @Entity annotation marks the class as a JPA entity, and @Id identifies the primary key column.

Code:

@Entity
public class Student {

    @Id
    @GeneratedValue(strategy = 
GenerationType.IDENTITY)
    private Long id;

    private String name;
    private String email;

    // Getters and Setters
}

Explanation

Create a Repository interface to perform database operations. Spring Data JPA automatically provides implementations for common CRUD operations.

Code:

import org.springframework.data.jpa.
repository.JpaRepository;

public interface StudentRepository
 extends JpaRepository<Student, Long> {
}

Explanation

Use the repository inside a REST controller to fetch and store data in the MySQL database. Dependency injection is handled using the @Autowired annotation.

Code:

@RestController
@RequestMapping("/students")
public class StudentController {

    @Autowired
    private StudentRepository repository;

    @GetMapping
    public List<Student> getStudents() {
        return repository.findAll();
    }
}

Explanation

Create new records in the database using a POST API. The incoming JSON request is converted into a Student object and saved using the repository.

Code:

@PostMapping
public Student createStudent(
@RequestBody Student student) {
    return repository.save(student);
}