Spring OneToMany relation with composite key to another with a composite key - spring

Question

I want to have a ManyToOne relation between 2 classes (Chapter & Camera). A chapter object contains many Camera objects.
The problem is my parent class (Chapter) already has a composite key.
Chapter composite key:
#Embeddable
public class ChapterKey implements Serializable {
#Column(name = "Chapter_ID", nullable = false)
private int chapterID;
#Column(name = "Operation_FK", nullable = false)
private int operationFK;
}
Chapter class:
#Entity
public class Chapter implements Serializable
{
private static final long serialVersionUID = 1L;
#EmbeddedId
private ChapterKey chapterKey;
#Column(name="Chapter_Name")
private String chapterName;
#Column(name="Chapter_Description")
private String chapterDescription;
#Column(name="Chapter_View_Range")
private int chapterViewRangeInterval;
#Column(name="Chapter_Video_Length")
private int chapterVideoLength;
}
Camera key:
#Embeddable
public class CameraKey implements Serializable {
#Column(name = "Camera_ID", nullable = false)
private int cameraID;
#Column(name = "Chapter_FK", nullable = false)
private int chapterFK;
#Column(name = "Operation_FK", nullable = false)
private int operationFK;
}
Camera class:
#Entity
public class Camera implements Serializable
{
private static final long serialVersionUID = 1L;
#EmbeddedId
private CameraKey cameraKey;
#Column(name="Camera_Description")
private String cameraDescription;
#Column(name="Camera_Usage")
private int cameraUsage;
#Column(name="Video_URL")
private String videoURL;
}
My question is, how do i make a OneToMany relationship between those 2 classes?

Answer 1

This answer for chapter side pk(Chapter_ID, Operation_FK) and camera side pk(camera_id,chapter_fk,operation_fk)
ER for is below.
Chapter.class is
#Entity
public class Chapter implements Serializable {
private static final long serialVersionUID = 1L;
#EmbeddedId
protected ChapterPK chapterPK;
#Basic(optional = false)
#Column(name = "chapter_name", nullable = false, length = 12)
private String chapterName;
#Basic(optional = false)
#Column(name = "chapter_description", nullable = false, length = 12)
private String chapterDescription;
#Basic(optional = false)
#Column(name = "chapter_Vvew_range", nullable = false)
private int chapterVvewrange;
#Basic(optional = false)
#Column(name = "chapter_video_length", nullable = false)
private int chapterVideoLength;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "chapter")
private Collection<Camera> cameraCollection;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "chapter1")
private Collection<Camera> cameraCollection1;
}
ChapterPK.class
#Embeddable
public class ChapterPK implements Serializable {
#Basic(optional = false)
#Column(name = "chapter_id", nullable = false)
private int chapterId;
#Basic(optional = false)
#Column(name = "operation_fk", nullable = false)
private int operationFk;
}
Camera.class
#Entity
public class Camera implements Serializable {
private static final long serialVersionUID = 1L;
#EmbeddedId
protected CameraPK cameraPK;
#Basic(optional = false)
#Column(name = "camera_description", nullable = false, length = 12)
private String cameraDescription;
#Basic(optional = false)
#Column(name = "camera_usage", nullable = false)
private int cameraUsage;
#Basic(optional = false)
#Column(name = "video_url", nullable = false)
private int videoUrl;
#JoinColumn(name = "chapter_fk", referencedColumnName = "chapter_id", nullable = false, insertable = false, updatable = false)
#ManyToOne(optional = false)
private Chapter chapter;
#JoinColumn(name = "operation_fk", referencedColumnName = "operation_fk", nullable = false, insertable = false, updatable = false)
#ManyToOne(optional = false)
private Chapter chapter1;
}
CameraPK.class
#Embeddable
public class CameraPK implements Serializable {
#Basic(optional = false)
#Column(name = "camera_id", nullable = false)
private int cameraId;
#Basic(optional = false)
#Column(name = "chapter_fk", nullable = false)
private int chapterFk;
#Basic(optional = false)
#Column(name = "operation_fk", nullable = false)
private int operationFk;
}
In here both side has two way binding.

Answer 2

This is ER for pk(camera_id) & pk(chapter_id,operation_fk) problem
This is a Chapter class.
#Entity
public class Camera implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#Basic(optional = false)
#Column(name = "camera_id", nullable = false)
private Integer cameraId;
#Basic(optional = false)
#Column(name = "camera_description", nullable = false, length = 12)
private String cameraDescription;
#Basic(optional = false)
#Column(name = "camera_usage", nullable = false)
private int cameraUsage;
#Basic(optional = false)
#Column(name = "video_url", nullable = false)
private int videoUrl;
#JoinColumn(name = "chapter_fk", referencedColumnName = "chapter_id", nullable = false)
#ManyToOne(optional = false, fetch = FetchType.EAGER)
private Chapter chapterFk;
#JoinColumn(name = "operation_fk", referencedColumnName = "operation_fk", nullable = false)
#ManyToOne(optional = false, fetch = FetchType.EAGER)
private Chapter operationFk;
}
this is ChapterPK.class that define primary key of your chapter class. it has composite primary key.
#Embeddable
public class ChapterPK implements Serializable {
#Basic(optional = false)
#Column(name = "chapter_id", nullable = false)
private int chapterId;
#Basic(optional = false)
#Column(name = "operation_fk", nullable = false)
private int operationFk;
}
finally camera.class
#Entity
public class Chapter implements Serializable {
private static final long serialVersionUID = 1L;
#EmbeddedId
protected ChapterPK chapterPK;
#Basic(optional = false)
#Column(name = "chapter_name", nullable = false, length = 12)
private String chapterName;
#Basic(optional = false)
#Column(name = "chapter_description", nullable = false, length = 12)
private String chapterDescription;
#Basic(optional = false)
#Column(name = "chapter_Vvew_range", nullable = false)
private int chapterVvewrange;
#Basic(optional = false)
#Column(name = "chapter_video_length", nullable = false)
private int chapterVideoLength;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "chapterFk", fetch = FetchType.EAGER)
private Collection<Camera> cameraCollection;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "operationFk", fetch = FetchType.EAGER)
private Collection<Camera> cameraCollection1;
}
In here I use two way binding in both chapter and camera classes. if you are using composite primary key. you have to manage additional embedded primary key object.