`User.hbm.xml`

特别关注inverse="false"和<index column="EVENT_INDEX" />：

<hibernate-mapping package="demidov.pkg.domain">
    <class name="TheUser" table="USER">
        <id name="userId" column="ID" type="integer">
            <generator class="native"/>         
        </id>

        <property name="userFirstName" column="FIRST_NAME" type="string" not-null="true"/>
        <property name="userLastName" column="LAST_NAME" type="string"/>
        <property name="userEmail" column="EMAIL" type="string" not-null="true"/>
        <property name="personAddress" column="PERSON_ADDRESS" type="string" />
        <property name="personPhoneNumber" column="PERSON_PHONE" type="string" />
        <property name="userGender" column="GENDER" type="string"/>

        <list name="userEventsList" inverse="false" lazy="true" fetch="select" cascade="all" >
            <key column="USER_ID" not-null="true" />
            <index column="EVENT_INDEX" />          
            <one-to-many class="UserEvents"/>       
        </list>
    </class>
</hibernate-mapping>

`UserEvents.hbm.xml`

特别关注<many-to-one name="theUser" class="TheUser" insert="false" update="false" lazy="false" fetch="select" cascade="save-update">

<hibernate-mapping package="demidov.pkg.domain">
    <class name="UserEvents" table="USER_EVENTS">
        <id name="userEventId" column="ID" type="integer">
            <generator class="native"/>
        </id>
        <property name="userEventDate" column="EVENT_DATE" type="date"/>
        <many-to-one name="theUser" class="TheUser" insert="false" update="false" lazy="false" fetch="select" cascade="save-update">
            <column name="USER_ID" not-null="true"/>
        </many-to-one>

        <joined-subclass name="ComputerMaintenanceEvent" table="MAINTENANCE_EVENT">
        <key column="MAINTENANCE_ID" not-null="true"/>
        <property name="descriptionMaintenance" column="DESCRIPTION_MAINTENANCE" type="string"/>
            <property name="additionalInfoMaintenance" column="ADDITIONAL_INFO_MAINTENANCE" type="string"/>
        </joined-subclass>              

        <joined-subclass name="SoftwareDevelopmentEvent" table="DEVELOPMENT_EVENT">
        <key column="DEVELOPMENT_ID" not-null="true"/>
        <property name="descriptionDevelopment" column="DESCRIPTION_DEVELOPMENT" type="string"/>
        <property name="additionalInfoDevelopment" column="ADDITIONAL_INFO_DEVELOPMENT" type="string"/>
        </joined-subclass>
    </class>
</hibernate-mapping>

因为我的User.hbm.xml是inverse="false"而我的UserEvents.hbm.xml是insert="false" update="false"当我想将user + userevents保存到我的数据库时，我的<index column="EVENT_INDEX/>会得到更新，我将对集合中的元素进行索引计数（0,1,2等）。像这样：

+----+------------+---------+-------------+----------------+-------------------------+-----------------------------+
| ID | EVENT_DATE | USER_ID | EVENT_INDEX | MAINTENANCE_ID | DESCRIPTION_MAINTENANCE | ADDITIONAL_INFO_MAINTENANCE |
+----+------------+---------+-------------+----------------+-------------------------+-----------------------------+
|  1 | 2013-10-31 |       1 |           0 |              2 | Description maitnance   |  Maitnance Test             |
|  2 | 2013-10-31 |       1 |           1 |              2 | Description maitnance   |  Maitnance Test             |
+----+------------+---------+-------------+----------------+-------------------------+-----------------------------+

但当我的User.hbm.xml inverse="true"和我的UserEvents.hbm.xml insert="true" update="true"中有<index column="EVENT_INDEX/>并希望将用户+ userevents保存到我的数据库时，我的{{1}在数据库中，插入集合的每个元素都有null个值。像这样：

+----+------------+---------+-------------+----------------+-------------------------+-----------------------------+
| ID | EVENT_DATE | USER_ID | EVENT_INDEX | DEVELOPMENT_ID | DESCRIPTION_DEVELOPMENT | ADDITIONAL_INFO_DEVELOPMENT |
+----+------------+---------+-------------+----------------+-------------------------+-----------------------------+
|  1 | 2013-10-31 |       1 |        NULL |              1 | Develop                 | Development Test            |
|  2 | 2013-10-31 |       1 |        NULL |              1 | Develop                 | Development Test            |
+----+------------+---------+-------------+----------------+-------------------------+-----------------------------+

另一个问题，为什么我的hibernate插入复制相同的值，多次包括我的集合元素。正如您从表中看到的那样，我正在尝试将一个DESCRIPTION_DEVELOPMENT和一个DESCRIPTION_MAINTENANCE对象保存到DB - ＆gt;它们在一个集合中，但是hibernate将它们保存两次，因为我在同一个集合中有2个但是不同的元素。

我如何插入：

List<UserEvents> eventList  = new ArrayList<UserEvents>();

SoftwareDevelopmentEvent sde = new SoftwareDevelopmentEvent();
sde.setDescriptionDevelopment("Develop");
sde.setAdditionalInfoDevelopment("Development Test");
sde.setUserEventDate(new Date());
eventList.add(sde);

ComputerMaintenanceEvent cme = new ComputerMaintenanceEvent();
cme.setDescriptionMaintenance("Description maitnance");
cme.setAdditionalInfoMaintenance(" Maitnance Test");
cme.setUserEventDate(new Date());
eventList.add(cme);

TheUser user = new TheUser();
user.setUserFirstName("Vadim1");
user.setUserLastName("Dem1");
user.setUserGender("Male1");
user.setUserEmail("vad@mail.ru");
user.setPersonAddress("Adress");
user.setPersonPhoneNumber("1111111");

user.setUserEventsList(eventList);

dao.saveUser(user);

DAO方法很简单：

public void saveUser(TheUser user) {
    Session session = sessionFactory.getCurrentSession();
    session.save(user);
}

Answer 1

请在此处查看我的帖子。

Java - Hibernate @ManyToMany mapping adds records in the database only in one direction

您需要设置关系的两侧。

e.g。 cme.setUser（用户）;

艾伦

Hibernate：为什么索引列仅在inverse =“false”时更新

`User.hbm.xml`

`UserEvents.hbm.xml`

1 个答案: