Add more examples

Author: dndanov

spring-data-jpa-entity/src/main/java/com/github/dndanoff/db/PersistOrderDemo.java

@@ -0,0 +1,41 @@
+package com.github.dndanoff.db;
+
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.core.annotation.Order;
+import org.springframework.stereotype.Component;
+
+import jakarta.persistence.EntityManager;
+import jakarta.persistence.PersistenceContext;
+import jakarta.transaction.Transactional;
+
+@Transactional
+@Component
+@Order(4)
+public class PersistOrderDemo implements CommandLineRunner {
+
+    @PersistenceContext
+    private EntityManager em;
+
+    @Override
+    public void run(String... args) {
+        if (true) {
+            StudentDemoEntity student = new StudentDemoEntity();
+            student.setFirstName("Denis");
+            student.setLastName("Danov");
+            student.setFacultyNumber("M_TEST@@@");
+            em.persist(student);
+
+            em.remove(student);
+
+            StudentDemoEntity newStudent = new StudentDemoEntity();
+            newStudent.setFirstName("Denis");
+            newStudent.setLastName("Nikolaev Danov");
+            newStudent.setFacultyNumber("M_TEST@@@");
+            em.persist(newStudent);
+
+            // THIS IS THE FIX
+            // student.setLastName("Nikolaev Danov");
+            // em.persist(student);
+        }
+    }
+}

spring-data-jpa-entity/src/main/java/com/github/dndanoff/db/SpringTransactionDemo.java

@@ -18,7 +18,7 @@ public class SpringTransactionDemo implements CommandLineRunner {
 
     @Override
     public void run(String... args) {
-        if (true) {
+        if (false) {
             StudentDemoEntity student = new StudentDemoEntity();
             student.setFirstName("Denis");
             student.setLastName("Danov");

spring-data-jpa-entity/src/main/resources/application.properties

@@ -9,7 +9,7 @@ spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
 spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQLDialect
 
 # controls schema creation from hibernate
-spring.jpa.hibernate.ddl-auto=none
+spring.jpa.hibernate.ddl-auto=create
 # use names exactly as in the table annotation
 spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
 # How to import data to the DB

spring-data-jpa/src/main/java/com/github/dndanoff/db/SpringJpaDemoRunner.java renamed to spring-data-jpa/src/main/java/com/github/dndanoff/db/CustomJpaMethodsDemo.java

@@ -9,10 +9,10 @@
 
 @Component
 @Order(2)
-public class SpringJpaDemoRunner implements CommandLineRunner {
+public class CustomJpaMethodsDemo implements CommandLineRunner {
     private StudentRepository repo;
 
-    public SpringJpaDemoRunner(StudentRepository repo) {
+    public CustomJpaMethodsDemo(StudentRepository repo) {
         this.repo = repo;
     }
 
@@ -22,8 +22,14 @@ public void run(String... args) {
             Student student = new Student("M-test1");
             student.setFirstName("Denis");
             student.setLastName("Danov");
+            repo.save(student);
 
+            student.setLastName("Nikolaev Danov");
             repo.save(student);
+
+            System.out.println(repo.customFind("M-test1"));
+            System.out.println(repo.customNativeFind("M-test1"));
+            System.out.println(repo.totallyCustomMethod("M-test1"));
         }
     }
 }

spring-data-jpa/src/main/java/com/github/dndanoff/db/RelationsDemo.java

@@ -0,0 +1,35 @@
+package com.github.dndanoff.db;
+
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.core.annotation.Order;
+import org.springframework.stereotype.Component;
+
+import com.github.dndanoff.db.entity.dummyrelations.*;
+
+import jakarta.persistence.EntityManager;
+import jakarta.persistence.PersistenceContext;
+import jakarta.transaction.Transactional;
+
+@Transactional
+@Component
+@Order(1)
+public class RelationsDemo implements CommandLineRunner {
+
+    @PersistenceContext
+    private EntityManager em;
+
+    @Override
+    public void run(String... args) {
+        if (false) {
+            DummyFaculty fmi = new DummyFaculty();
+            fmi.setName("FMI");
+
+            DummyStudent student = new DummyStudent("M_TEST");
+            student.setFirstName("Denis");
+            student.setLastName("Danov");
+            fmi.addStudent(student);
+
+            em.persist(fmi);
+        }
+    }
+}

spring-data-jpa/src/main/java/com/github/dndanoff/db/RelationsDemoRunner.java

@@ -20,7 +20,7 @@ public class Faculty {
     private Long id;
     @Column(length = 255, nullable = false, unique = true)
     private String name;
-    @OneToMany(mappedBy = "faculty", cascade = CascadeType.ALL, orphanRemoval = true)
+    @OneToMany(cascade = CascadeType.ALL, mappedBy = "faculty", orphanRemoval = true)
     private Set<Student> students = new HashSet<>();
 
     public void addStudent(Student student) {

spring-data-jpa/src/main/java/com/github/dndanoff/db/entity/Faculty.java

@@ -60,7 +60,7 @@ public String toString() {
                 firstName,
                 lastName,
                 facultyNumber,
-                created.format(DateTimeFormatter.ISO_LOCAL_DATE_TIME),
+                created != null ? created.format(DateTimeFormatter.ISO_LOCAL_DATE_TIME) : null,
                 deleted != null ? deleted.format(DateTimeFormatter.ISO_LOCAL_DATE_TIME) : null);
     }
 

spring-data-jpa/src/main/java/com/github/dndanoff/db/entity/Student.java

@@ -0,0 +1,60 @@
+package com.github.dndanoff.db.entity.dummyrelations;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
+
+@Entity
+@Table(name = "DUMMY_FACULTIES")
+public class DummyFaculty {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+    @Column(length = 255, nullable = false, unique = true)
+    private String name;
+    @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
+    private Set<DummyStudent> students = new HashSet<>();
+
+    public void addStudent(DummyStudent student) {
+        students.add(student);
+    }
+
+    public void removeStudent(DummyStudent student) {
+        students.remove(student);
+    }
+
+    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;
+    }
+
+    public Set<DummyStudent> getStudents() {
+        return new HashSet<>(students);
+    }
+
+    public void setStudents(Set<DummyStudent> students) {
+        if (students != null) {
+            this.students = students;
+        }
+    }
+}

spring-data-jpa/src/main/java/com/github/dndanoff/db/entity/dummyrelations/DummyFaculty.java

@@ -0,0 +1,118 @@
+package com.github.dndanoff.db.entity.dummyrelations;
+
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Index;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+import jakarta.persistence.Transient;
+
+@Entity
+@Table(name = "DUMMY_STUDENTS", indexes = {
+        @Index(name = "facultyNum_uniqueIndex", columnList = "facultyNumber", unique = true)
+})
+public class DummyStudent {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+    @Column(length = 255, nullable = false)
+    private String firstName;
+    @Column(length = 255, nullable = false)
+    private String lastName;
+    @Column(length = 20, unique = true, nullable = false)
+    private String facultyNumber;
+    @Transient
+    private String notPersistedAtribute;
+    @Column(columnDefinition = "TIMESTAMP DEFAULT CURRENT_TIMESTAMP")
+    private LocalDateTime created;
+    private LocalDateTime deleted;
+    @ManyToOne
+    private DummyFaculty faculty;
+
+    // natural key is passed here so that it has value for new entities
+    public DummyStudent(String facultyNumber) {
+        this.facultyNumber = facultyNumber;
+    }
+
+    protected DummyStudent() {
+    }
+
+    public String toString() {
+        return String.format("ID: %d, FIRST_NAME: %s, LAST_NAME: %s, FACULTY_NUMBER: %s, CREATED: %s, DELETED: %s", id,
+                firstName,
+                lastName,
+                facultyNumber,
+                created.format(DateTimeFormatter.ISO_LOCAL_DATE_TIME),
+                deleted != null ? deleted.format(DateTimeFormatter.ISO_LOCAL_DATE_TIME) : null);
+    }
+
+    // There is a natural key so we use it in equals. PAy attention the natural key
+    // is required in the constructor
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (!(o instanceof DummyStudent))
+            return false;
+        return facultyNumber.equals(((DummyStudent) o).getFacultyNumber());
+    }
+
+    @Override
+    public int hashCode() {
+        return getFacultyNumber().hashCode();
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public String getFacultyNumber() {
+        return facultyNumber;
+    }
+
+    public void setFacultyNumber(String facultyNumber) {
+        this.facultyNumber = facultyNumber;
+    }
+
+    public LocalDateTime getCreated() {
+        return created;
+    }
+
+    public void setCreated(LocalDateTime created) {
+        this.created = created;
+    }
+
+    public LocalDateTime getDeleted() {
+        return deleted;
+    }
+
+    public void setDeleted(LocalDateTime deleted) {
+        this.deleted = deleted;
+    }
+}