Hibernate的cascade属性 特别是 cascadeType.all的 作用

1.JPA中的CascadeType.ALL并不等于{CascadeType.PESIST,CascadeType.REMOVE,CascadeType.MERGE,CascadeType.REFRESH}

 

在Hibernate中调用session.save() or session.update()并不能触发 {CascadeType.PESIST,CascadeType.REMOVE,CascadeType.MERGE,CascadeType.REFRESH} 的级联操作，而能触发CascadeType.ALL的级联。如不希望用CascadeType.ALL，需要使用Hibernate自身对 cascade的注解 @Cascade(value=org.hibernate.annotations.CascadeType.SAVE_UPDATE)

 

2.共享主键的OneToOne方式不能通过cascade来自动生成标识符 ，即使声明了@GenericGenerator(name="foreign_key",strategy="foreign",parameters={@Parameter(name="property",value="person")})

<p style="margin-top: 0px; margin-bottom: 10px; padding-top: 0px; padding-bottom: 0px;"><span class="lit" style="color: rgb(0, 102, 102);">@Entity</span><span class="kwd" style="color: rgb(0, 0, 136);">public</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">class</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">Person</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">implements</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">Serializable</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">        </span><span class="lit" style="color: rgb(0, 102, 102);">@Id</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="lit" style="color: rgb(0, 102, 102);">@GeneratedValue</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">generator </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"g_id"</span><span class="pun" style="color: rgb(102, 102, 0);">)</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">public</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">String</span><span class="pln" style="color: rgb(0, 0, 0);"> getId</span><span class="pun" style="color: rgb(102, 102, 0);">()</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">  </span><span class="kwd" style="color: rgb(0, 0, 136);">return</span><span class="pln" style="color: rgb(0, 0, 0);"> id</span><span class="pun" style="color: rgb(102, 102, 0);">;</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pln" style="color: rgb(0, 0, 0);">         </span><span class="lit" style="color: rgb(0, 102, 102);">@OneToOne</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">cascade </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">CascadeType</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">PERSIST </span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="typ" style="color: rgb(102, 0, 102);">CascadeType</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">ALL</span><span class="pun" style="color: rgb(102, 102, 0);">})</span><span class="pln" style="color: rgb(0, 0, 0);">         </span><span class="lit" style="color: rgb(0, 102, 102);">@JoinColumn</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">name </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"profile_id"</span><span class="pun" style="color: rgb(102, 102, 0);">)</span><span class="pln" style="color: rgb(0, 0, 0);">  </span><span class="lit" style="color: rgb(0, 102, 102);">@PrimaryKeyJoinColumn</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">name</span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="str" style="color: rgb(0, 136, 0);">"id"</span><span class="pun" style="color: rgb(102, 102, 0);">)</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">public</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">Profile</span><span class="pln" style="color: rgb(0, 0, 0);"> getProfile</span><span class="pun" style="color: rgb(102, 102, 0);">()</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">  </span><span class="kwd" style="color: rgb(0, 0, 136);">return</span><span class="pln" style="color: rgb(0, 0, 0);"> profile</span><span class="pun" style="color: rgb(102, 102, 0);">;</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="lit" style="color: rgb(0, 102, 102);">@Entity</span><span class="kwd" style="color: rgb(0, 0, 136);">public</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">class</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">Profile</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">implements</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">Serializable</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">        </span><span class="lit" style="color: rgb(0, 102, 102);">@Id</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="lit" style="color: rgb(0, 102, 102);">@GenericGenerator</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">name </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"foreign_key"</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> strategy </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"foreign"</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> parameters </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="lit" style="color: rgb(0, 102, 102);">@Parameter</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">name </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"property"</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> value </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"person"</span><span class="pun" style="color: rgb(102, 102, 0);">)</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">})</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="lit" style="color: rgb(0, 102, 102);">@GeneratedValue</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">generator </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"foreign_key"</span><span class="pun" style="color: rgb(102, 102, 0);">)</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">public</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">String</span><span class="pln" style="color: rgb(0, 0, 0);"> getId</span><span class="pun" style="color: rgb(102, 102, 0);">()</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">  </span><span class="kwd" style="color: rgb(0, 0, 136);">return</span><span class="pln" style="color: rgb(0, 0, 0);"> id</span><span class="pun" style="color: rgb(102, 102, 0);">;</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);">        </span><span class="lit" style="color: rgb(0, 102, 102);">@OneToOne</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">mappedBy </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"profile"</span><span class="pun" style="color: rgb(102, 102, 0);">)</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">public</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">Person</span><span class="pln" style="color: rgb(0, 0, 0);"> getPerson</span><span class="pun" style="color: rgb(102, 102, 0);">()</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">  </span><span class="kwd" style="color: rgb(0, 0, 136);">return</span><span class="pln" style="color: rgb(0, 0, 0);"> person</span><span class="pun" style="color: rgb(102, 102, 0);">;</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">public</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">void</span><span class="pln" style="color: rgb(0, 0, 0);"> setPerson</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">Person</span><span class="pln" style="color: rgb(0, 0, 0);"> person</span><span class="pun" style="color: rgb(102, 102, 0);">)</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">  </span><span class="kwd" style="color: rgb(0, 0, 136);">this</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">person </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> person</span><span class="pun" style="color: rgb(102, 102, 0);">;</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pun" style="color: rgb(102, 102, 0);">}</span></p>

3.delete-orphan只应用在OneToMany中，能级联删除Many集合中的子元素。

   NOTE:JPA并不支持delete-orphan，但并不明白hibernate reference中为什么可以在OneToMany中添加属性orphanRemoval=true的属性。事实上，要用hibernate独有的注解 @Cascade(value=@CascadeType.DELETE_ORPHAN)来达到此目的。

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cascade属性的可能值有     all: 所有情况下均进行关联操作，即save-update和delete。     none: 所有情况下均不进行关联操作。这是默认值。      save-update: 在执行save/update/saveOrUpdate时进行关联操作。      delete: 在执行delete 时进行关联操作。      all-delete-orphan: 当一个节点在对象图中成为孤儿节点时，删除该节点。比如在一个一对多的关系中，Student包含多个book，当在对象关系中删除一个book时，此book即成为孤儿节点。