休眠產生不正確的更新語句

Question

我有這樣的：

String hql = "UPDATE User u SET u.externalId = u.id WHERE u.directory.name = 'MySuperAwesomeName' AND u.externalId = null"; 
    Query query = session().createQuery(hql); 
    query.executeUpdate(); 

而且休眠拋出異常說：

Unexpected token JOIN, requires SET in statement [update user cross join set external_id=id where name='MySuperAwesomeName' and (external_id is null)] 

請幫我指點我做錯了什麼。

映射爲用戶實體：

<?xml version="1.0"?> 
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> 
<hibernate-mapping> 
    <class name="com.example.User" table="user" lazy="true"> 
     <id name="id" column="id" unsaved-value="null"> 
      <generator class="com.example.MySuperAwesomeGenerator"/> 
     </id> 
     <property name="name" column="user_name" type="string" not-null="true" length="255"/> 
     <property name="externalId" column="external_id" type="string" not-null="false" length="255" index="idx_external_id"/> 
     <many-to-one name="directory" column="directory_id" not-null="true" foreign-key="fk_user_dir_id" unique-key="uk_user_name_dir_id" class="com.example.DirectoryImpl"/> 
    </class> 
</hibernate-mapping> 

Answer 1

答案可能會改變這個查詢到的查詢與小的子查詢

UPDATE User u SET u.externalId = u.id WHERE u.directory.id IN (SELECT d.id FROM DirectoryImpl d where d.name = 'MySuperAwesomeName') AND u.externalId = NULL 

它的工作原理。