我嘗試在兩個表之間創建一對一的關係。與休眠一對一關係
其中之一就是人:
public class Person implements Serializable {
static final long serialVersionUID = 1L;
private long id;
private String _email;
private String _pass;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getEmail() {
return _email;
}
public void set_email(String _email) {
this._email = _email;
}
public String getPass() {
return _pass;
}
public void set_pass(String _pass) {
this._pass = _pass;
}
}
,第二個是ReqC2dmRegId表:現在
public class ReqC2dmRegId implements Serializable {
private static final long serialVersionUID = 1L;
Person person;
String C2dmid;
private long id;
public ReqC2dmRegId(){}
public String getC2dmid() {
return C2dmid;
}
public void setC2dmid(String c2dmid) {
C2dmid = c2dmid;
}
public ReqC2dmRegId(Person person, String C2dmid) {
super();
this.person = person;
this.C2dmid = C2dmid;
}
public Person getPerson() {
return person;
}
public void setPerson(Person person) {
this.person = person;
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
}
,在我的節目,我總是創造Person
第一,只有當我需要我補充這ReqC2dmRegId
。
現在,我試圖做的是鏈接這兩個表。我的意思是,當我堅持這個ReqC2dmRegId
(當然我加入ReqC2dmRegId
的人的正確ID)我想我的ReqC2dmRegId
到更新或保存一個新的行與正確的Person
ID。
這些都是我的HBM文件:
ReqC2dmRegId.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated Mar 26, 2012 11:29:57 AM by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
<class name="c2dm.ReqC2dmRegId" table="REQC2DMREGID">
<id name="id" type="long">
<generator class="foreign">
<param name="property">person</param>
</generator>
</id>
<one-to-one name="person" class="Entities.Person" cascade="all" />
<property name="C2dmid" type="java.lang.String">
<column name="C2DMID" />
</property>
</class>
</hibernate-mapping>
Person.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated Mar 26, 2012 11:29:57 AM by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
<class name="Entities.Person" table="PERSON">
<id name="id" type="long">
<column name="ID" />
<generator class="increment" />
</id>
<property name="_email" type="java.lang.String" access="field">
<column name="_EMAIL" />
</property>
<property name="_pass" type="java.lang.String" access="field">
<column name="_PASS" />
</property>
</class>
</hibernate-mapping>
我在做什麼錯?
當我嘗試運行:
//this should to update or save the object in DB
public void update (Object query){
EntityManager em = emf.createEntityManager();
em.getTransaction().begin();
//em.createNativeQuery(query).executeUpdate();
em.merge(query);
em.flush();
em.getTransaction().commit();
em.close();
}
我得到:
attempted to assign id from null one-to-one property:Person
最後,它應該是這樣的:
人
**id email _pass**
2 [email protected] 1234
ReqC2dmRegId
**id REQC2DMREGID**
2 ffgghhjj
更新: 後,我放棄了試圖理解方式,它不工作
我改變ReqC2dmRegId.hbm.xml 看起來像這樣(多到一):
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <!-- Generated Mar 27, 2012 9:58:08 PM by Hibernate Tools 3.4.0.CR1 --> <hibernate-mapping>
<class name="c2dm.ReqC2dmRegId" table="REQC2DMREGID">
<id name="id" type="long">
<column name="ID" />
<generator class="identity" />
</id>
<many-to-one name="person" class="Entities.Person" fetch="join" unique="true" cascade="save-update" not-null="true" >
<column name="PERSON" />
</many-to-one>
<property name="C2dmid" type="java.lang.String">
<column name="C2DMID" />
</property>
</class> </hibernate-mapping>
,這是工作的罰款的問題是,當我試圖修改ReqC2dmRegId表 我更新的方法是創建一個與現在相同PERSONID
排它不更新正確的行安裝創建一個新的,雖然我讓「多對一」屬性是唯一=「真」?
在此先感謝
你爲什麼不使用註釋,而不是XML文件?我發現註解容易,更直觀 – suenda 2012-03-27 19:53:54
在開始時我發現xml對我來說更容易,出於某種原因..我開始與他們合作,現在很難改變我的所有對象。 – user986474 2012-03-27 20:29:34