Java Hibernate映射文件无法正常工作 [英] Java Hibernate Mapping File not working

问题描述

我得到的错误是org.hibernate.MappingException：实体映射中的重复列：cdd.model.Answer column：answer_id（应该用insert =falseupdate =false映射） 即可。但是，当我把这些作为属性，我得到的错误：必须为元素类型ID声明属性插入。

任何帮助将不胜感激。

Class：

  public class Answer {
 UUID answer ID; 
字符串内容; 
 
 //构造函数和getter和setters 
 
} 
  

Table：

  CREATE TABLE IF NOT EXISTS回答（
 
 answer_id uuid NOT NULL，
 content text NOT NULL，
主键（answer_id）
）; 
  

Hibernate映射文件：

 <！ - > ====回答====<！ - > 
< class name =cdd.model.Answertable =answer> 
< id column =answer_idname =answerID
 type =org.hibernate.type.PostgresUUIDType
 insert =falseupdate =false> 
< generator class =org.hibernate.id.UUIDGenerator/> 
< / id> 
 
< property column =contentname =contenttype =org.hibernate.type.TextType/> 
< / class> 
  

注意
我有一个问题类，一组答案。这是我使用的映射。我张贴它，因为我gettng错误可能是因为我如何映射此一对多关系（我不确定）。

 <！ -  ====问题====  - > 
< class name =cdd.model.Questiontable =question> 
< id column =question_idname =questionIDtype =org.hibernate.type.PostgresUUIDType> 
< generator class =org.hibernate.id.UUIDGenerator/> 
< / id> 
  <多对一列=parentCategoryname =parentCategorynot-null =true/> 
 
< property column =titlename =titletype =org.hibernate.type.TextType/> 
< property column =correct_answername =correctAnswertype =org.hibernate.type.TextType/> 
< property column =date_submittedname =dateSubmittedtype =org.hibernate.type.TimestampType/> 
 
 < key column =answer_idnot-null =true/> 
 < / set> 
 
< join inverse =trueoptional =truetable =category_questions> 
< key column =question_id/> 
< / join> 
< join inverse =trueoptional =truetable =accepted_questions_by_user> 
< key column =question_id/> 
< / join> 
< / class> 
  

解决方案

问题实体：

 < id column =question_idname =questionIDtype =org.hibernate.type.PostgresUUIDType> 
< generator class =org.hibernate.id.UUIDGenerator/> 
< / id> 
  

答案实体：

 < id column =answer_idname =answerIDtype =org.hibernate.type.PostgresUUIDType
 insert =falseupdate =false> 
< generator class =org.hibernate.id.UUIDGenerator/> 
< / id> 
  

删除 insert =falseupdate =false


应该看起来像这样

 来自Answr实体的$ c> < id column =answer_idname =answerIDtype =org.hibernate.type.PostgresUUIDType> 
< generator class =org.hibernate.id.UUIDGenerator/> 
< / id> 
  

update，insert（可选 - 默认为true）：指定映射列应包含在SQL UPDATE和/或INSERT语句。将两者都设置为false允许一个纯粹的派生属性，其值由映射到相同列的其他属性或触发器或其他应用程序初始化。

The error I get is " org.hibernate.MappingException: Repeated column in mapping for entity: cdd.model.Answer column: answer_id (should be mapped with insert="false" update="false") ". However when I put those as attributes I get the error: "Attribute "insert" must be declared for element type "id"."

Any help would be appreciated.

Class:

public class Answer {
UUID answerID;
String content;

//constructors and getters and setters

}

Table:

    CREATE TABLE IF NOT EXISTS answer (

    answer_id uuid NOT NULL ,
    content text NOT NULL,
    primary key(answer_id)
    );

Hibernate Mapping File:

<!-->==== Answer ====<!-->
<class name="cdd.model.Answer" table="answer" >
<id column="answer_id" name="answerID" 
    type="org.hibernate.type.PostgresUUIDType"  
    insert="false" update="false">
  <generator class="org.hibernate.id.UUIDGenerator"/>
</id>

<property column="content" name="content" type="org.hibernate.type.TextType"/>
</class>

Note I have a Question class where a question has a set of answers. This is the mapping I used. I am posting it because the error I'm gettng may be because of how I mapped this one-to-many relationship (I'm not sure).

<!-- ==== Question ==== -->
<class name="cdd.model.Question" table="question">
<id column="question_id" name="questionID" type="org.hibernate.type.PostgresUUIDType">
  <   generator class="org.hibernate.id.UUIDGenerator"/>
</id>
<many-to-one column="submitted_by" name="submittedBy" not-null="true"/>
<many-to-one column="parentCategory" name="parentCategory" not-null="true"/>

<property column="title" name="title" type="org.hibernate.type.TextType"/>
<property column="correct_answer" name="correctAnswer" type="org.hibernate.type.TextType"/>
<property column="date_submitted" name="dateSubmitted" type="org.hibernate.type.TimestampType"/>

<set cascade="all" name="answers" table="answer">
  <key column="answer_id" not-null="true"/>
  <one-to-many class="cdd.model.Answer"/>
</set>

<join inverse="true" optional="true" table="category_questions">
  <key column="question_id"/>
</join>
<join inverse="true" optional="true" table="accepted_questions_by_user">
  <key column="question_id"/>
</join>
</class>

解决方案

Question Entity:

<id column="question_id" name="questionID" type="org.hibernate.type.PostgresUUIDType">
  <generator class="org.hibernate.id.UUIDGenerator"/>
</id>

Answer Entity:

<id column="answer_id" name="answerID" type="org.hibernate.type.PostgresUUIDType"  
    insert="false" update="false">
  <generator class="org.hibernate.id.UUIDGenerator"/>
</id>

remove insert="false" update="false" from Answr entity

should look someting like this

<id column="answer_id" name="answerID" type="org.hibernate.type.PostgresUUIDType" >
  <generator class="org.hibernate.id.UUIDGenerator"/>
</id>

update, insert (optional - defaults to true): specifies that the mapped columns should be included in SQL UPDATE and/or INSERT statements. Setting both to false allows a pure "derived" property whose value is initialized from some other property that maps to the same column(s), or by a trigger or other application.

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