Best one-to-many mapping

Author: AnghelLeonard

HibernateSpringBootOneToManyBidirectional/src/main/java/com/bookstore/MainApplication.java

@@ -22,14 +22,14 @@ public static void main(String[] args) {
     @Bean
     public ApplicationRunner init() {
         return args -> {
-            System.out.println("\nAdd author with books  ...");
-            bookstoreService.addAuthorWithBooks();
+            System.out.println("\nInsert author with books  ...");
+            bookstoreService.insertAuthorWithBooks();
 
-            System.out.println("\nRemove a book of an author...");
-            bookstoreService.removeBookOfAuthor();
+            System.out.println("\nDelete a book of an author...");
+            bookstoreService.deleteBookOfAuthor();
 
-            System.out.println("\nRemove all book of an author...");
-            bookstoreService.removeAllBooksOfAuthor();
+            System.out.println("\nDelete all book of an author...");
+            bookstoreService.deleteAllBooksOfAuthor();
         };
     }
 }

HibernateSpringBootOneToManyBidirectional/src/main/java/com/bookstore/repository/AuthorRepository.java

@@ -2,12 +2,14 @@
 
 import com.bookstore.entity.Author;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
 import org.springframework.stereotype.Repository;
 import org.springframework.transaction.annotation.Transactional;
 
 @Repository
+@Transactional(readOnly=true)
 public interface AuthorRepository extends JpaRepository<Author, Long> {
-    
-    @Transactional(readOnly=true)
-    Author findByName(String name);
+        
+    @Query("SELECT a FROM Author a JOIN FETCH a.books WHERE a.name = ?1")
+    Author fetchByName(String name);
 }

HibernateSpringBootOneToManyBidirectional/src/main/java/com/bookstore/repository/BookRepository.java

@@ -3,11 +3,7 @@
 import com.bookstore.entity.Book;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.stereotype.Repository;
-import org.springframework.transaction.annotation.Transactional;
 
 @Repository
 public interface BookRepository extends JpaRepository<Book, Long> {
-
-    @Transactional(readOnly = true)
-    Book findByTitle(String title);
 }

HibernateSpringBootOneToManyBidirectional/src/main/java/com/bookstore/service/BookstoreService.java

@@ -1,6 +1,5 @@
 package com.bookstore.service;
 
-import com.bookstore.repository.BookRepository;
 import com.bookstore.repository.AuthorRepository;
 import com.bookstore.entity.Author;
 import com.bookstore.entity.Book;
@@ -9,45 +8,42 @@
 
 @Service
 public class BookstoreService {
-   
+
     private final AuthorRepository authorRepository;
-    private final BookRepository bookRepository;
 
-    public BookstoreService(AuthorRepository authorRepository,
-            BookRepository bookRepository) {
+    public BookstoreService(AuthorRepository authorRepository) {
 
         this.authorRepository = authorRepository;
-        this.bookRepository = bookRepository;
     }
-   
-    public void addAuthorWithBooks(){
-        
+
+    public void insertAuthorWithBooks() {
+
         Author author = new Author();
         author.setName("Alicia Tom");
         author.setAge(38);
         author.setGenre("Anthology");
-        
+
         Book book = new Book();
         book.setIsbn("001-AT");
         book.setTitle("The book of swords");
-                
+
         author.addBook(book); // use addBook() helper
-        
+
         authorRepository.save(author);
     }
-    
+
     @Transactional
-    public void removeBookOfAuthor() {
-        
-        Author author = authorRepository.findByName("Alicia Tom");
-        Book book  = bookRepository.findByTitle("The book of swords");
-        
+    public void deleteBookOfAuthor() {
+
+        Author author = authorRepository.fetchByName("Alicia Tom");
+        Book book = author.getBooks().get(0);
+
         author.removeBook(book); // use removeBook() helper        
     }
-        
+
     @Transactional
-    public void removeAllBooksOfAuthor() {
-        Author author = authorRepository.findByName("Joana Nimar");
+    public void deleteAllBooksOfAuthor() {
+        Author author = authorRepository.fetchByName("Joana Nimar");
         author.removeBooks(); // use removeBooks() helper    
     }
 

HibernateSpringBootOneToManyBidirectional/src/main/resources/data-mysql.sql

@@ -1,8 +1,11 @@
-insert into author (age, name, genre, id) values (23, "Mark Janel", "Anthology", 1);
-insert into author (age, name, genre, id) values (43, "Olivia Goy", "Horror", 2);
-insert into author (age, name, genre, id) values (51, "Quartis Young", "Anthology", 3);
-insert into author (age, name, genre, id) values (34, "Joana Nimar", "History", 4);
-insert into book (isbn, title, author_id, id) values ("001-JN", "A History of Ancient Prague", 4, 1);
-insert into book (isbn, title, author_id, id) values ("002-JN", "A People's History", 4, 2);
-insert into book (isbn, title, author_id, id) values ("001-MJ", "The Beatles Anthology", 1, 3);
-insert into book (isbn, title, author_id, id) values ("001-OG", "Carrie", 2, 4);
+-- insert authors
+INSERT INTO `author` (`age`, `name`, `genre`, `id`) VALUES (23, "Mark Janel", "Anthology", 1);
+INSERT INTO `author` (`age`, `name`, `genre`, `id`) VALUES (43, "Olivia Goy", "Horror", 2);
+INSERT INTO `author` (`age`, `name`, `genre`, `id`) VALUES (51, "Quartis Young", "Anthology", 3);
+INSERT INTO `author` (`age`, `name`, `genre`, `id`) VALUES (34, "Joana Nimar", "History", 4);
+
+-- insert books
+INSERT INTO `book` (`isbn`, `title`, `author_id`, `id`) VALUES ("001-JN", "A History of Ancient Prague", 4, 1);
+INSERT INTO `book` (`isbn`, `title`, `author_id`, `id`) VALUES ("002-JN", "A People's History", 4, 2);
+INSERT INTO `book` (`isbn`, `title`, `author_id`, `id`) VALUES ("001-MJ", "The Beatles Anthology", 1, 3);
+INSERT INTO `book` (`isbn`, `title`, `author_id`, `id`) VALUES ("001-OG", "Carrie", 2, 4);