added Author Entity

Author: tsiupa-coder

src/main/java/com/example/model/Author.java

@@ -0,0 +1,38 @@
+package com.example.model;
+
+import org.hibernate.annotations.BatchSize;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "authors")
+@BatchSize(size = 10)
+public class Author {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    Long id;
+    @Column(name = "full_name")
+    String name;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+}

src/main/java/com/example/model/Book.java

@@ -10,9 +10,12 @@ public class Book {
     private Long id;
     private String title;
     private int pages;
-
     private int year;
 
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "author_id")
+    private Author author;
+
     public Book(String title, int pages) {
         this.title = title;
         this.pages = pages;
@@ -52,4 +55,12 @@ public int getYear() {
     public void setYear(int year) {
         this.year = year;
     }
+
+    public Author getAuthor() {
+        return author;
+    }
+
+    public void setAuthor(Author author) {
+        this.author = author;
+    }
 }

src/main/java/com/example/repository/AuthorRepository.java

@@ -0,0 +1,9 @@
+package com.example.repository;
+
+import com.example.model.Author;
+import io.micronaut.data.annotation.Repository;
+import io.micronaut.data.repository.CrudRepository;
+
+@Repository
+public interface AuthorRepository  extends CrudRepository<Author, Long> {
+}

src/main/java/com/example/repository/BookRepository.java

@@ -3,16 +3,21 @@
 import com.example.model.Book;
 import io.micronaut.context.annotation.Executable;
 import io.micronaut.data.annotation.*;
+import io.micronaut.data.jpa.annotation.EntityGraph;
+import io.micronaut.data.jpa.repository.JpaSpecificationExecutor;
 import io.micronaut.data.repository.CrudRepository;
 
-@Repository // 
-interface BookRepository extends CrudRepository<Book, Long> {
-
-    @Executable
-    Book find(String title);
-
+import java.util.List;
 
+@Repository
+public interface BookRepository extends CrudRepository<Book, Long>, JpaSpecificationExecutor<Book> {
 
+    @Executable
+    Book findByTitle(String title);
 
+    @Join(value = "author", type = Join.Type.FETCH) //
+    List<Book> list();
 
+    @EntityGraph(attributePaths = {"author", "title"}) //
+    List<Book> findAll();
 }

src/main/java/com/example/service/AuthorService.java

@@ -0,0 +1,19 @@
+package com.example.service;
+
+import com.example.repository.AuthorRepository;
+import io.micronaut.context.annotation.Primary;
+import jakarta.inject.Inject;
+import jakarta.inject.Singleton;
+
+@Primary
+@Singleton
+public class AuthorService {
+
+    @Inject
+    AuthorRepository repository;
+
+
+    public void getAll(){
+        repository.findAll();
+    }
+}

src/main/java/com/example/service/BookService.java

@@ -1,7 +1,7 @@
 package com.example.service;
 
-import com.example.BookRepository;
 import com.example.model.Book;
+import com.example.repository.BookRepository;
 import io.micronaut.context.annotation.Primary;
 import jakarta.inject.Inject;
 import jakarta.inject.Singleton;
@@ -30,7 +30,7 @@ public void initDataBase(){
     @Transactional
     public List<Book> findAll(){
 
-        return (List<Book>) repository.findAll();
+        return repository.findAll();
     }
 
     @Transactional

src/main/resources/application.yml

@@ -14,10 +14,11 @@ datasources:
     username: 'sa'
     password: ''
     driverClassName: 'org.h2.Driver'
+
 jpa:
   default:
-    packages-to-scan:
-      - 'com.example'
+    entity-scan:
+      packages: 'com.example.model'
     properties:
       hibernate:
         hbm2ddl:

src/main/resources/db/liquibase-changelog.xml

@@ -5,6 +5,7 @@
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
          http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.1.xsd">
+
     <changeSet id="001" author="ivan_tsiupa">
       <sql>
           CREATE TABLE IF NOT EXISTS books
@@ -47,4 +48,35 @@
             UPDATE books SET year = 2007 WHERE title = 'Deathly Hallows';
         </sql>
     </changeSet>
+
+    <changeSet id="005" author="ivan_tsiupa">
+        <sql>
+            CREATE TABLE IF NOT EXISTS authors (
+                id          BIGSERIAL    NOT NULL,
+                full_name   TEXT         NOT NULL,
+                PRIMARY KEY (id)
+            );
+        </sql>
+    </changeSet>
+
+    <changeSet id="006" author="ivan_tsiupa">
+        <sql>
+            INSERT INTO authors(full_name) VALUES('J. K. Rowling');
+        </sql>
+    </changeSet>
+
+
+    <changeSet id="007" author="ivan_tsiupa">
+        <sql>
+            ALTER TABLE books ADD author_id BIGINT constraint author_id_constraint references authors;
+        </sql>
+    </changeSet>
+
+    <changeSet id="008" author="ivan_tsiupa">
+        <sql>
+            UPDATE books SET author_id = 1;
+        </sql>
+    </changeSet>
+
+
 </databaseChangeLog>