Java Hibernate，在不加载集合的情况下更新包含集合的对象

我有一个项目，其中包含一组列，其中包含一组任务，其中包含一组TaskAssigness

我正在尝试更新列标题，而不必加载其任务集，但出现以下错误：

[AssertionFailure] - an assertion failure occured (this may indicate a bug in Hibernate, but is more likely due to unsafe use of the session)
    org.hibernate.AssertionFailure: collection [com.example.tasks.Task.taskAssignees] was not processed by flush() 

我有以下hbm.xml:

Project.hbm.xml：

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "classpath://org/hibernate/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
  <class name="com.exemple.tasks.project.Project" table="P_TASKS_PROJECT">
    <cache usage="read-write" />
    <id name="rowId" column="rowId">
      <generator class="native"/>
    </id>
    ...
    <set name="columns" table="P_TASK_PROJECT_COLUMN" inverse="true" cascade="all" sort="com.exemple.tasks.project.ColumnIndexComparator">
      <cache usage="read-write" />
      <key column="projectId" not-null="true" />
      <one-to-many class="com.exemple.tasks.project.Column" />
    </set>

  </class>
</hibernate-mapping>

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "classpath://org/hibernate/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
  <class name="com.example.tasks.project.Column" table="P_TASK_PROJECT_COLUMN">
    <cache usage="read-write" />
    <id name="rowId" column="rowId">
      <generator class="native"/>
    </id>
    ...
    <property name="title" />
    <many-to-one name="project" class="com.example.tasks.project.Project">
      <column name="projectId" not-null="false" />
    </many-to-one>

    <set name="tasks" table="P_TASKS_JOIN_COLUMNS">
      <cache usage="read-write" />
      <key column="columnId" not-null="true" />
      <many-to-many column="taskId" class="com.example.tasks.Task" unique="false" />
    </set>
  </class>
</hibernate-mapping>

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "classpath://org/hibernate/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
  <class name="com.example.tasks.Task" table="P_TASK">
    <cache usage="read-write" />
    <id name="rowId" column="rowId">
      <generator class="native"/>
    </id>
    ...
    <set name="taskAssignees" table="P_TASK_ASSIGNEE" cascade="all-delete-orphan">
      <cache usage="read-write" />
      <key column="taskId" not-null="true" />
      <one-to-many class="com.example.tasks.TaskAssignee" />
    </set>

  </class>
</hibernate-mapping>

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "classpath://org/hibernate/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
  <class name="com.example.tasks.TaskAssignee" table="P_TASK_ASSIGNEE">
    <cache usage="read-write" />
    <id name="rowId" column="rowId">
      <generator class="native"/>
    </id>
    ...
    <many-to-one name="task" class="com.example.tasks.Task" insert="false" update="false">
      <column name="taskId" not-null="true" />
    </many-to-one>

  </class>
</hibernate-mapping>

如果列中不包含任何任务，则此操作可以正常工作。 如果我尝试更新包含任务的列，则会收到以下错误消息：

[AssertionFailure] - an assertion failure occured (this may indicate a bug in Hibernate, but is more likely due to unsafe use of the session)
org.hibernate.AssertionFailure: collection [com.example.tasks.Task.taskAssignees] was not processed by flush() 

如果我在更新项目之前获得tasks和tasks assigness，则我没有错误：

Set<Task> tasks = col.getTasks();
  if (tasks != null) {
    for (Task task : tasks) {
      task.getTaskAssignees();
     }
   }
session.saveOrUpdate(project);

Set tasks=col.getTasks（）；
如果（任务！=null）{
for（任务：任务）{
task.getTaskAssignees（）；
}
}
会议.保存或更新（项目）；

有没有办法更改我的专栏标题，然后更新项目，而不必获取任务和任务受让人？我可以告诉hibernate只更新列而不尝试进一步吗

Set<Task> tasks = col.getTasks();
  if (tasks != null) {
    for (Task task : tasks) {
      task.getTaskAssignees();
     }
   }
session.saveOrUpdate(project);