happen error on update Tutor!
"You may not change the reference to a collection with cascade=\"all-delete-orphan\""
teacher.hbm.xml and tutor.hbm.xml
Code:
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0" schema="dbo">
  <class name="UniversityEntity.Model.Person, UniversityEntity" table="Person">
    <id name="Id" type="Int32" column="PersonId"  access="nosetter.pascalcase-m-underscore" unsaved-value="0">
      <generator class="identity" />
    </id>
    <bag name="Resumes" inverse="true" cascade="all-delete-orphan">
      <key column="Person_PersonId" />
      <one-to-many class="UniversityEntity.Model.Resume, UniversityEntity" />
    </bag>
    <bag name="Relations" inverse="true" cascade="all-delete-orphan">
      <key column="Person_PersonId" />
      <one-to-many class="UniversityEntity.Model.Relation, UniversityEntity" />
    </bag>
    <property name="Birthday" column="Birthday" type="DateTime" />
    <property name="Clan" column="Clan" type="String" />
    <property name="EducationLevel" column="EducationLevel" type="String" />
    <property name="Folk" column="Folk" type="String" />
    <one-to-one name="Family" cascade="all" class="UniversityEntity.Model.Family, UniversityEntity" />
    <property name="Hearth" column="Hearth" type="String" />
    <property name="IsOverseasChinese" column="IsOverseasChinese" type="Boolean" />
    <property name="Name" column="Name" type="String" />
    <property name="NativePlace" column="NativePlace" type="String" />
    <property name="Oldname" column="Oldname" type="String" />
    <property name="Pic" column="Pic" type="BinaryBlob" length="4001" />
    <property name="Sex" column="Sex" type="String" />
    <property name="TopDegree" column="TopDegree" type="String" />
    <property name="Title" column="Title" type="String" />
    <one-to-one name="SocietySecurtyCard" cascade="all" class="UniversityEntity.Model.SocietySecurtyCard, UniversityEntity" />
    <property name="Password" column="Password" type="String" />
    <property name="LoginName" column="LoginName" type="String" />
    
    <!-- Begin 教师子类 -->
    <joined-subclass name="UniversityEntity.Model.Teacher,UniversityEntity" table="Teacher"> 
      <key column="TeacherId"/>    
      <property name="TeacherNo" column="TeacherNo" type="String" />       
      <bag name="StudentBases" inverse="true" cascade="none">
        <key column="PrimaryGuide_TeacherId" />
        <one-to-many class="UniversityEntity.Model.StudentBase, UniversityEntity" />
      </bag>
      <bag name="OtherStudentBases" table="StudentBase_Teacher" cascade="none">
        <key column="TeacherId" />
        <many-to-many column="StudentBaseId" class="UniversityEntity.Model.StudentBase, UniversityEntity" />
      </bag>
    </joined-subclass>
    <!-- End 教师子类 -->
    
    <!-- Begin 学生子类 -->
    <joined-subclass name="UniversityEntity.Model.StudentBase,UniversityEntity" table="StudentBase"> 
      <key column="StudentBaseId"/>
      <one-to-one name="TeachPlanForStudent"  class="UniversityEntity.Model.TeachPlanForStudent, UniversityEntity" />
      <many-to-one name="PrimaryGuide" column="PrimaryGuide_TeacherId" class="UniversityEntity.Model.Teacher, UniversityEntity"/>
      <bag name="OtherGuides" table="StudentBase_Teacher">
        <key column="StudentBaseId" />
        <many-to-many column="TeacherId" class="UniversityEntity.Model.Teacher, UniversityEntity" />
      </bag>
      <bag name="Graduates" inverse="true" cascade="all">
        <key column="StudentBase_StudentBaseId" />
        <one-to-many class="UniversityEntity.Model.Graduate, UniversityEntity" />
      </bag>
      <many-to-one name="DegreeGrade" column="DegreeGrade_DegreeGradeID" class="UniversityEntity.Model.DegreeGrade, UniversityEntity"/>
      <many-to-one name="ProfessionalDirector" column="ProfessionalDirector_Id" class="UniversityEntity.Model.ProfessionalDirector, UniversityEntity" />
      <property name="EntranceDate" column="EntranceDate" type="DateTime" />
      <property name="PartTimeHeadship" column="PartTimeHeadship" type="String" />
      <many-to-one name="WorkUnit" column="WorkUnit_WorkUnitId" class="UniversityEntity.Model.WorkUnit, UniversityEntity" cascade="all" />
      <property name="StudentNo" column="StudentNo" type="String" />   
      <many-to-one name="ClassInfo" column="ClassInfo_ClassInfoId" class="UniversityEntity.Model.ClassInfo, UniversityEntity"/>
    </joined-subclass>
    <!-- End 学生子类 -->
  </class>
</hibernate-mapping>
Code:
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0" schema="dbo">
  <class name="UniversityEntity.Model.Tutor, UniversityEntity" table="Tutor">
    <id name="Id" type="Int32" column="TutorId" access="nosetter.pascalcase-m-underscore" unsaved-value="0">
      <generator class="foreign">         
         <param name="property">Teacher</param>
      </generator>
    </id>
    <property name="FirstMasterTutorDate" column="FirstMasterTutorDate" type="DateTime"/>
    <property name="FirstDoctorTutorDate" column="FirstDoctorTutorDate" type="DateTime" />
    <property name="IsStarted" column="IsStarted" type="Boolean" />
    <property name="IsProhibited" column="IsProhibited" type="Boolean" />
    <property name="Reason" column="Reason" type="String" />
    <bag name="ProfessionalDirectores"  cascade="none" table="Tutor_ProfessionalDirector">
     <key column="Tutor_TutorId" />
     <many-to-many class="UniversityEntity.Model.ProfessionalDirector, UniversityEntity" column ="ProfessionalDirector_ProfessionalDirectorId"/>
   </bag>
    <many-to-one name="TutorType" column="TutorType_TutorTypeId" class="UniversityEntity.Model.TutorType, UniversityEntity" unique="true"/>
    <many-to-one name="University" column="University_UniversityId" class="UniversityEntity.Model.University, UniversityEntity" unique="true"/>
    <many-to-one name="Institute" column="Institute_InstituteId" class="UniversityEntity.Model.Institute, UniversityEntity" unique="true"/>
    <many-to-one name="ResearchIntroduce" column="FormatedText_FormatedTextId" class="UniversityEntity.Model.FormatedText, UniversityEntity" unique="true"/>
    <one-to-one name="Teacher" class="UniversityEntity.Model.Teacher,UniversityEntity" constrained="true" />
  </class>
</hibernate-mapping>
[/code]