add named queries tutorial

spring-data-jpa/jpa-queries/README.md

@@ -2,3 +2,4 @@
 
 - [Derived Query Methods in Spring Data JPA](https://attacomsian.com/blog/derived-query-methods-spring-data-jpa)
 - [Spring Data JPA Custom Queries with the @Query Annotation](https://attacomsian.com/blog/spring-data-jpa-query-annotation)
+- [How to Use Spring Data JPA Named Queries](https://attacomsian.com/blog/spring-data-jpa-named-queries)

spring-data-jpa/jpa-queries/src/main/java/com/attacomsian/jpa/Application.java

@@ -4,6 +4,8 @@
 import com.attacomsian.jpa.custom.repositories.NoteRepository;
 import com.attacomsian.jpa.derived.domains.User;
 import com.attacomsian.jpa.derived.repositories.UserRepository;
+import com.attacomsian.jpa.named.domains.Book;
+import com.attacomsian.jpa.named.repositories.BookRepository;
 import org.springframework.boot.CommandLineRunner;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
@@ -14,17 +16,25 @@
 import org.springframework.data.domain.Sort;
 import org.springframework.data.jpa.domain.JpaSort;
 
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
 import java.util.List;
 
 @SpringBootApplication
 public class Application {
 
+    @PersistenceContext
+    private EntityManager em;
+
     public static void main(String[] args) {
         SpringApplication.run(Application.class, args);
     }
 
     @Bean
-    public CommandLineRunner runner(UserRepository userRepository, NoteRepository noteRepository) {
+    public CommandLineRunner runner(UserRepository userRepository,
+                                    NoteRepository noteRepository,
+                                    BookRepository bookRepository) {
         return args -> {
             // Like pattern
 //            String pattern = "%atta%@gmail%";
@@ -35,15 +45,38 @@ public CommandLineRunner runner(UserRepository userRepository, NoteRepository no
 //            Page<User> userPage = userRepository.findByActive(true, pageable);
 
             // notes sorting
-            List<Note> startupNotes = noteRepository.findByTitle("startup", Sort.by("title").ascending());
+//            List<Note> startupNotes = noteRepository.findByTitle("startup", Sort.by("title").ascending());
+//            List<Note> techNotes = noteRepository.findByTitle("tech", Sort.by("priority").descending());
+//            List<Note> lengthyNotes = noteRepository.findByTitle("tech", JpaSort.unsafe("LENGTH(title)"));
 
-            List<Note> techNotes = noteRepository.findByTitle("tech", Sort.by("priority").descending());
+            // notes pagination
+//            Pageable pageable = PageRequest.of(0, 10, Sort.by("title").descending());
+//            Page<Note> notePage = noteRepository.findAllNotesWithPagination(pageable);
 
-            List<Note> lengthyNotes = noteRepository.findByTitle("tech", JpaSort.unsafe("LENGTH(title)"));
+            // create books
+            bookRepository.save(new Book("Java 101", "145804", 450));
+            bookRepository.save(new Book("Spring Bot", "48524", 289));
 
-            // notes pagination
-            Pageable pageable = PageRequest.of(0, 10, Sort.by("title").descending());
-            Page<Note> notePage = noteRepository.findAllNotesWithPagination(pageable);
+            // execute named queries with `EntityManager`
+//            Query q = em.createNamedQuery("Book.findByTitleJPQL");
+//            q.setParameter(1, "Java 101");
+//            // execute query
+//            List<Book> books = q.getResultList();
+//
+            // execute native sql named query
+//            Query q = em.createNamedQuery("Book.findByIsbnNative");
+//            q.setParameter("isbn", "145804");
+//            // execute query
+//            Book book = (Book) q.getSingleResult();
+
+            // list all books
+            List<Book> books = bookRepository.findAllXML();
+
+            // fetch a single book
+            Book book = bookRepository.findByIsbnNamedFile("145804");
+
+            // multiple parameters
+            List<Book> moreBooks = bookRepository.findByTitleAndPagesGreaterThanJPQL("Spring Bot", 150);
         };
     }
 

spring-data-jpa/jpa-queries/src/main/java/com/attacomsian/jpa/named/domains/Book.java

@@ -0,0 +1,96 @@
+package com.attacomsian.jpa.named.domains;
+
+import javax.persistence.*;
+import java.util.Objects;
+
+@Entity
+@NamedQueries({
+        @NamedQuery(name = "Book.findAllJPQL",
+                query = "SELECT b FROM Book b ORDER BY b.title DESC"),
+        @NamedQuery(name = "Book.findByTitleJPQL",
+                query = "SELECT b FROM Book b WHERE b.title = ?1"),
+        @NamedQuery(name = "Book.findByTitleAndPagesGreaterThanJPQL",
+                query = "SELECT b FROM Book b WHERE b.title = :title AND b.pages > :pages")
+})
+@NamedNativeQueries({
+        @NamedNativeQuery(name = "Book.findAllNative",
+                query = "SELECT * FROM book b ORDER BY b.title DESC",
+                resultClass = Book.class),
+        @NamedNativeQuery(name = "Book.findByIsbnNative",
+                query = "SELECT * FROM book b WHERE b.isbn = :isbn",
+                resultClass = Book.class)
+})
+public class Book {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private Long id;
+    private String title;
+    @Column(unique = true)
+    private String isbn;
+    private int pages;
+
+    public Book() {
+    }
+
+    public Book(String title, String isbn, int pages) {
+        this.title = title;
+        this.isbn = isbn;
+        this.pages = pages;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getIsbn() {
+        return isbn;
+    }
+
+    public void setIsbn(String isbn) {
+        this.isbn = isbn;
+    }
+
+    public int getPages() {
+        return pages;
+    }
+
+    public void setPages(int pages) {
+        this.pages = pages;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Book book = (Book) o;
+        return id.equals(book.id);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id);
+    }
+
+    @Override
+    public String toString() {
+        return "Book{" +
+                "id=" + id +
+                ", title='" + title + '\'' +
+                ", isbn='" + isbn + '\'' +
+                ", pages=" + pages +
+                '}';
+    }
+}

spring-data-jpa/jpa-queries/src/main/java/com/attacomsian/jpa/named/repositories/BookRepository.java

@@ -0,0 +1,47 @@
+package com.attacomsian.jpa.named.repositories;
+
+import com.attacomsian.jpa.named.domains.Book;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.query.Param;
+
+import java.util.List;
+
+public interface BookRepository extends CrudRepository<Book, Long> {
+
+    // named queries declared in `jpa-named-queries.properties` file
+
+    List<Book> findAllNamedFile();
+
+    List<Book> findByTitleNamedFile(String title);
+
+    Book findByIsbnNamedFile(String isbn);
+
+    @Query(nativeQuery = true)
+    List<Book> findByTitleNativeNamedFile(@Param("title") String title);
+
+    // named queries declared in `orm.xml` file
+
+    List<Book> findAllXML();
+
+    List<Book> findByTitleContainingXML(String title);
+
+    @Query(nativeQuery = true)
+    List<Book> findByIsbnNativeXML(@Param("isbn") String isbn);
+
+    // named queries declared with `@NamedQuery`
+
+    List<Book> findAllJPQL();
+
+    List<Book> findByTitleJPQL(String title);
+
+    List<Book> findByTitleAndPagesGreaterThanJPQL(@Param("title") String title, @Param("pages") int pages);
+
+    // named queries declared with `@NamedNativeQuery`
+
+    @Query(nativeQuery = true)
+    List<Book> findAllNative();
+
+    @Query(nativeQuery = true)
+    List<Book> findByIsbnNative(@Param("isbn") String isbn);
+}

spring-data-jpa/jpa-queries/src/main/resources/META-INF/jpa-named-queries.properties

@@ -0,0 +1,11 @@
+# find all books order by title descending
+Book.findAllNamedFile=SELECT b FROM Book b ORDER BY b.title DESC
+
+# find books by title
+Book.findByTitleNamedFile=SELECT b FROM Book b WHERE b.title = ?1
+
+# find a book by isbn
+Book.findByIsbnNamedFile=SELECT b FROM Book b WHERE b.isbn = ?1
+
+# native SQL query to find books by title
+Book.findByTitleNativeNamedFile=SELECT * FROM book b WHERE b.title = :title

spring-data-jpa/jpa-queries/src/main/resources/META-INF/orm.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<entity-mappings version="2.0" xmlns="http://java.sun.com/xml/ns/persistence/orm"
+                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+                 xsi:schemaLocation="http://java.sun.com/xml/ns/persistence/orm
+        http://java.sun.com/xml/ns/persistence/orm_2_0.xsd ">
+
+    <!--find all books order by pages descending-->
+    <named-query name="Book.findAllXML">
+        <query>SELECT b FROM Book b ORDER BY b.pages DESC</query>
+    </named-query>
+
+    <!--find books by title-->
+    <named-query name="Book.findByTitleContainingXML">
+        <query>SELECT b FROM Book b WHERE b.title LIKE ?1</query>
+    </named-query>
+
+    <!--native SQL query to find a book by isbn-->
+    <named-native-query name="Book.findByIsbnNativeXML"
+                        result-class="com.attacomsian.jpa.named.domains.Book">
+        <query>SELECT * FROM book b WHERE b.isbn = :isbn</query>
+    </named-native-query>
+
+</entity-mappings>