joincolumn + bidirectional mapping + mapped to wrong number of columns - spring-boot

Question

I have 3 entities
Parent Entity with primary key as parentId
Child Entity with primary key as child id and has parentId as foreign key. Here parentId and some Enum has unique constraint
GrandChild Entity with grandChildId as primary key and parentId, Enum as foreign key reference. Here parentId, Enum and grandChildId has unique constraint
#1, #2, #3 are working.
GreatGrandChild Entity where greatGrandChildId is primary key and foreign key as parentId, childEnum, grandChildId. But this is not working. It says
"A foreign key referring to granchild from greatgrandchild has the wrong number of column. It should be 1.
Now i tried just adding grandChildId as foreign key to GreatGrandChild table and it works. I have two questions
Why is parentId, ChildEnum and grandChildId not getting copied as foreign key whereas it works find upto a level above.
how i can make this work, I want Great Granchild to have foreign key of parent, Child and grand Child.
#Entity
#Setter #Getter #NoArgsConstructor #AllArgsConstructor #Build(toBuilder=true)
Class Parent{
#Id
private Long parentId;
///
#Builder.Default
#OneToMany(cascade = CascadeType.All, fetch = FetchType.Lazy, orphanRemoval = true, mappedBy = "parent)
#JsonManagedReference
private Set<Child> children = new HashSet();
public void addChild(Child Child){
children.add(child);
child.setParent(this);
}
public void removeChild(Child child){
children.remove(child);
child.setParent(null);
}
Child Entity
#Entity
#Setter #Getter #NoArgsConstructor #AllArgsConstructor #Build(toBuilder=true)
#Table (UniqueConstraints = {#UniqueConstraint(ColumnNames = {"parentId" , "childEnum"})})
Class Child{
#Id
private Long childId;
#Column
#Enumerated(EnumType.String)
private WeekDays childEnum; //some Enum
///
#ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
#JoinColumn(name="parentId", nullable=false)
private Parent parent;
#Builder.Default
#OneToMany(cascade = CascadeType.All, fetch = FetchType.Lazy, orphanRemoval = true, mappedBy = "child)
#JsonManagedReference
private Set<GrandChild> grandChildren = new HashSet();
public void addGrandChild(GrandChild grandChild){
grandChildren.add(grandChild);
grandChild.setChild(this);
}
public void removeGrandChild(GrandChild grandChild){
grandChildren.remove(grandChild);
grandChild.setChild(null);
}
GrandChild
#Entity
#Setter #Getter #NoArgsConstructor #AllArgsConstructor #Build(toBuilder=true)
#Table (UniqueConstraints = {#UniqueConstraint(ColumnNames = {"parentId" , "childEnum", "grandChildId"})})
Class GrandChild{
#Id
private Long grandchildId;
///
#ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
#JoinColumn(name="parentId", nullable=false)
#JoinColumn(name="childEnum", nullable=false)
private Child child;
#Builder.Default
#OneToMany(cascade = CascadeType.All, fetch = FetchType.Lazy, orphanRemoval = true, mappedBy = "grandChild)
#JsonManagedReference
private Set<GreatGrandChild> greatGrandchildren = new HashSet();
public void addGreatGrandChild(GreatGrandChild greatGrandChild){
greatGrandChildren.add(child);
greatGrandChild.setGrandChild(this);
}
public void removeGreatGrandChild(GreatGrandChild greatGrandChild){
greatGrandChildren.remove(greatGrandChild);
greatGrandChild.setGrandChild(null);
}
Great Grand Child
#Entity
#Setter #Getter #NoArgsConstructor #AllArgsConstructor #Build(toBuilder=true)
Class GreatGrandChild{
#Id
private Long greatGrandchildId;
///
#ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
#JoinColumn(name="parentId", nullable=false)
#JoinColumn(name="childEnum,", nullable=false)
#JoinColumn(name="grandChildId", nullable=false)
private GrandChild grandChild;
/// EDIT
in the GrandChild Class i removed parentId from unique Constraints. It only has childEnum and granchildId as unique constraints. ManyToOne mapping looks like this
#ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
#JoinColumn(name="parentId", nullable=false)
#JoinColumn(name="grandChildId", nullable=false)
private GrandChild grandChild;
I get the error as
referencedcolumn names does not map to a single entity.