하이버네이트를 사용하면서 제일 머리아픈게 @OneToOne인 것 같다.&nbsp; 완벽 정리를 하고 싶으나 능력이 미천하여 샘플만 하나 남겨본다. 아래와 같은 방법으로 해결이 된 것 같은데, 추후 사용하다 다시 업데이트 해야 할 것 같다. <div class="txc-textbox" style="border-style: solid; border-width: 1px; border-color: rgb(254, 254, 184); background-color: rgb(254, 254, 184); padding: 10px;"> public class Parent implements Serializable{

&nbsp;&nbsp;&nbsp;


&nbsp;&nbsp;&nbsp;
@Id

&nbsp;&nbsp;&nbsp;
@GeneratedValue

&nbsp;&nbsp;&nbsp;
private int
id

&nbsp;

&nbsp;&nbsp;&nbsp;
@OneToOne(mappedBy="parent", targetEntity=Children.class, fetch=FetchType.LAZY, orphanRemoval=true) 

&nbsp;&nbsp;&nbsp;
@org.hibernate.annotations.Cascade(org.hibernate.annotations.CascadeType.ALL)&nbsp;&nbsp; 

&nbsp;&nbsp;&nbsp;
private Children children;

&nbsp;&nbsp;&nbsp;


}

&nbsp;

public class Children&nbsp; implements
Serializable{

&nbsp;&nbsp;&nbsp;


&nbsp;&nbsp;&nbsp;
@OneToOne(optional=false, targetEntity=Parent.class, fetch=FetchType.LAZY)&nbsp; 

&nbsp;&nbsp;&nbsp;
@JoinColumns(value={ @JoinColumn(name="ParentId", referencedColumnName="ParentId",
nullable=false) }, foreignKey=@ForeignKey(name="FKtpo_policy787323"))

&nbsp;&nbsp;&nbsp;
private Parent parent;

&nbsp;&nbsp;&nbsp;


&nbsp;&nbsp;&nbsp;
@Column(name = "ParentId", columnDefinition =
"BINARY(16)", nullable =
false, insertable
= false, updatable =
false)

&nbsp;&nbsp;&nbsp;
@Id 

&nbsp;&nbsp;&nbsp;
private byte[] parentId;

&nbsp;&nbsp;&nbsp;


}

&nbsp;</div>

[JPA/Hibernate] @OneToOne