@Entity
@Table(name = "student")
public class Student {

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "student_generator")
    @SequenceGenerator(name = "student_generator", sequenceName = "student_sequence", allocationSize = 10)
    @Column(name = "student_id")
    private long id;

    @Column(name = "student_name")
    private String name;

    @Column(name = "student_age")
    private int age;

    @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
    @JoinColumn(name = "book_id")
    private Set<Books> books = new HashSet<Books>();

    public Student() {

    }

    public Student(long id) {
        this.id = id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public void setBooks(Set<Books> books) {
        this.books = books;
    }

    public Set<Books> getBooks() {
        return books;
    }

    public long getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public void addBook(Books book) {
        books.add(book);
        book.setStudent(this);
    }

    public void removeBook(Books book) {
        books.remove(book);
        book.setStudent(null);
    }

    @Override
    public String toString() {
        return "Student N: " + id + " name: " + name + " age: " + age;
    }

}

@Entity
@Table(name = "book")
public class Books {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "book_id")
    private long id;

    @Column(name = "bookName")
    private String bookName;

    @Column(name = "genre")
    private String genre;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "student_id")
    private Student student;

    public Books() {
    }

    public void setId(long id) {
        this.id = id;
    }

    public void setBookName(String bookName) {
        this.bookName = bookName;
    }

    public void setGenre(String genre) {
        this.genre = genre;
    }

    public long getId() {
        return id;
    }

    public String getBookName() {
        return bookName;
    }

    public String getGenre() {
        return genre;
    }

    public void setStudent(Student student) {
        this.student = student;
    }

    public Student getStudent() {
        return student;
    }


    @Override
    public boolean equals(Object obj) {
        if (this == obj) return true;
        if (!(obj instanceof Books)) return false;
        return id == ((Books) obj).id;
    }

    @Override
    public int hashCode() {
        return 31;
    }


}

<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.12</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-core -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.3.4.Final</version>
        </dependency>

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence
             http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
    <persistence-unit name="persistence">

        <properties>
            <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>
            <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/javahelps"/>
            <property name="hibernate.connection.autocommit" value="false"/>
            <property name="hibernate.connection.username" value="root"/>
            <property name="hibernate.connection.password" value="12345"/>
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect"/>
            <property name="hibernate.connection.CharSet" value="utf8"/>
            <property name="hibernate.connection.characterEncoding" value="utf8"/>
            <property name="hibernate.connection.useUnicode" value="true"/>
            <property name="hibernate.show_sql" value="true"/>
            <property name="hibernate.hbm2ddl.auto" value="update"/>
        </properties>
    </persistence-unit>
</persistence>

public class Main {

    public static void main(String... main) {
        EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory("persistence");
        EntityManager entityManager = entityManagerFactory.createEntityManager();

       Student student1 = new Student();
       student1.setName("Lucas");
       student1.setAge(21);

        Books book1 = new Books();
        book1.setBookName("Dark Tower");
        book1.setGenre("Dark Fantasy");

        Books book2 = new Books();
        book1.setBookName("It");
        book1.setGenre("Horror");

        student1.addBook(book1);
        student1.addBook(book2);


        entityManager.getTransaction().begin();

        // Произвожу транзакцию и пытаюсь создать в таблице student одну запись, а в book две записи
        entityManager.persist(student1);

        entityManager.getTransaction().commit();


        entityManager.close();


    }
}

mysql> select * from student;
+------------+-------------+--------------+
| student_id | student_age | student_name |
+------------+-------------+--------------+
|         52 |          21 | Lucas        |
+------------+-------------+--------------+
1 row in set (0,14 sec)

mysql> select * from book;
+---------+----------+--------+------------+
| book_id | bookName | genre  | student_id |
+---------+----------+--------+------------+
|      52 | It       | Horror |         52 |
+---------+----------+--------+------------+
1 row in set (0,04 sec)

Student student1 = new Student();
   student1.setName("Lucas");
   student1.setAge(21);

    Books book1 = new Books();
    book1.setBookName("Dark Tower");
    book1.setGenre("Dark Fantasy");

    Books book2 = new Books();
    book1.setBookName("It");
    book1.setGenre("Horror");

    entityManager.getTransaction().begin();

    // Вот так можно создать в таблице student одну запись, а в book две записи
    entityManager.persist(student1);
    book1.setSudent(student1);
    entityManager.persist(book1);
    book2.setSudent(student1);
    entityManager.persist(book2);


    entityManager.getTransaction().commit();


    entityManager.close();