Merge pull request #13875 from KingsleyAmankwah/master

JPA/Hibernate Associations

persistence-modules/hibernate-mapping-2/src/main/java/com/baeldung/associations/biredirectional/Course.java

@@ -0,0 +1,42 @@
+package com.baeldung.associations.biredirectional;
+import jakarta.persistence.*;
+import java.util.List;
+
+@Entity
+public class Course {
+
+    @Id
+    private Long id;
+
+    private String name;
+
+    @ManyToMany
+    @JoinTable(name = "course_student",
+        joinColumns = @JoinColumn(name = "course_id"),
+        inverseJoinColumns = @JoinColumn(name = "student_id"))
+    private List<Student> students;
+    
+    public List<Student> getStudents() {
+        return students;
+    }
+ 
+    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 void setStudents(List<Student> students) {
+        this.students = students;
+    }
+}

persistence-modules/hibernate-mapping-2/src/main/java/com/baeldung/associations/biredirectional/Department.java

@@ -0,0 +1,21 @@
+package com.baeldung.associations.biredirectional;
+
+import java.util.List;
+import jakarta.persistence.*;
+
+
+@Entity
+public class Department {
+
+    @Id
+    private Long id;
+
+    @OneToMany(mappedBy = "department")
+    private List<Employee> employees;
+
+      public List<Employee> getEmployees() {
+        return employees;
+    }
+ 
+
+}

persistence-modules/hibernate-mapping-2/src/main/java/com/baeldung/associations/biredirectional/Employee.java

@@ -0,0 +1,42 @@
+package com.baeldung.associations.biredirectional;
+
+import jakarta.persistence.*;
+
+
+@Entity
+public class Employee {
+
+    @Id
+    private Long id;
+
+    private String name;
+
+    @ManyToOne
+    @JoinColumn(name = "department_id")
+    private Department department;
+ 
+
+    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 Department getDepartment() {
+        return department;
+    }
+
+    public void setDepartment(Department department) {
+        this.department = department;
+    }
+}

persistence-modules/hibernate-mapping-2/src/main/java/com/baeldung/associations/biredirectional/Student.java

@@ -0,0 +1,43 @@
+package com.baeldung.associations.biredirectional;
+
+import java.util.List;
+
+import jakarta.persistence.*;
+
+@Entity
+public class Student {
+ 
+    @Id
+    private Long id;
+ 
+    private String name;
+ 
+    @ManyToMany(mappedBy = "students")
+    private List<Course> courses;
+
+    
+    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 List<Course> getCourses() {
+        return courses;
+    }
+
+    public void setCourses(List<Course> courses) {
+        this.courses = courses;
+    }
+}
+

persistence-modules/hibernate-mapping-2/src/main/java/com/baeldung/associations/unidirectional/Author.java

@@ -0,0 +1,40 @@
+package com.baeldung.associations.unidirectional;
+import jakarta.persistence.*;
+import java.util.Set;
+
+@Entity
+public class Author {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    private String name;
+
+    @ManyToMany(fetch = FetchType.LAZY, mappedBy = "authors")
+    private Set<Book> books;
+
+    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<Book> getBooks() {
+        return books;
+    }
+
+    public void setBooks(Set<Book> books) {
+        this.books = books;
+    }
+}

persistence-modules/hibernate-mapping-2/src/main/java/com/baeldung/associations/unidirectional/Book.java

@@ -0,0 +1,44 @@
+package com.baeldung.associations.unidirectional;
+
+import jakarta.persistence.*;
+import java.util.Set;
+
+@Entity
+public class Book {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    private String title;
+
+    @ManyToMany(fetch = FetchType.LAZY)
+    @JoinTable(name = "book_author",
+            joinColumns = @JoinColumn(name = "book_id"),
+            inverseJoinColumns = @JoinColumn(name = "author_id"))
+    private Set<Author> authors;
+
+    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 Set<Author> getAuthors() {
+        return authors;
+    }
+
+    public void setAuthors(Set<Author> authors) {
+        this.authors = authors;
+    }
+}

persistence-modules/hibernate-mapping-2/src/main/java/com/baeldung/associations/unidirectional/Department.java

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+package com.baeldung.associations.unidirectional;
+
+import jakarta.persistence.*;
+import java.util.List;
+
+@Entity
+public class Department {
+
+    @Id
+    private Long id;
+
+    @OneToMany(fetch = FetchType.LAZY)
+    @JoinColumn(name = "department_id")
+    private List<Employee> employees;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public List<Employee> getEmployees() {
+        return employees;
+    }
+
+    public void setEmployees(List<Employee> employees) {
+        this.employees = employees;
+    }
+}
+
+

persistence-modules/hibernate-mapping-2/src/main/java/com/baeldung/associations/unidirectional/Employee.java

@@ -0,0 +1,42 @@
+package com.baeldung.associations.unidirectional;
+import jakarta.persistence.*;
+
+@Entity
+public class Employee {
+
+    @Id
+    private Long id;
+
+    @OneToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "parking_spot_id")
+    private ParkingSpot parkingSpot;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "department_id")
+    private Department department;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public ParkingSpot getParkingSpot() {
+        return parkingSpot;
+    }
+
+    public void setParkingSpot(ParkingSpot parkingSpot) {
+        this.parkingSpot = parkingSpot;
+    }
+
+    public Department getDepartment() {
+        return department;
+    }
+
+    public void setDepartment(Department department) {
+        this.department = department;
+    }
+}
+

persistence-modules/hibernate-mapping-2/src/main/java/com/baeldung/associations/unidirectional/ParkingSpot.java

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+package com.baeldung.associations.unidirectional;
+
+import jakarta.persistence.*;
+
+@Entity
+public class ParkingSpot {
+
+    @Id
+    private Long id;
+
+}