[求助] Hibernate 左联接问题

Question

Userinfo.hbm.xml 文件: 
------------------------------------------------------------------------- 
<?xml version="1.0"?> 
<!DOCTYPE hibernate-mapping PUBLIC 
"-//Hibernate/Hibernate Mapping DTD//EN" 
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" > 
<hibernate-mapping package="com.kmi.expert.model"> 
<class name="Userinfo" table="USERINFO"> 
<meta attribute="sync-DAO">false</meta> 
<id name="id" type="integer" column="OID"> 
<generator class="org.hibernate.id.Assigned" /> 
</id> 
<property name="username" column="USERNAME" type="string" not-null="true" length="8" /> 
<property name="password" column="PASSWORD" type="string" not-null="true" length="20" /> 
<property name="loginname" column="LOGINNAME" type="string" not-null="true" length="20" /> 
<set name="Usergroupinfos" inverse="true" lazy="true"> 
<key column="OID" /> 
<one-to-many class="Usergroupinfo" /> 
</set> 
<set name="Userroleinfos" inverse="true" lazy="true"> 
<key column="OID" /> 
<one-to-many class="Userroleinfo" /> 
</set> 
</class> 
</hibernate-mapping>

Answer 1

Usergroupinfo.hbm.xml 文件: 
-------------------------------------------------------------------------<?xml version="1.0"?> 
<!DOCTYPE hibernate-mapping PUBLIC 
"-//Hibernate/Hibernate Mapping DTD//EN" 
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" > 
<hibernate-mapping package="com.kmi.expert.model"> 
<class name="Usergroupinfo" table="USERGROUPINFO"> 
<meta attribute="sync-DAO">false</meta> 
<id name="id" type="integer" column="OID"> 
<generator class="org.hibernate.id.Assigned" /> 
</id> 
<many-to-one name="userinfooid" column="USERINFOOID" class="Userinfo" not-null="true"></many-to-one> 
<many-to-one name="groupoid" column="GROUPOID" class="Groups" not-null="true"></many-to-one> 
</class> 
</hibernate-mapping>
如何才能正确的写出一个HQL

Answer 2

select a from com.kmi.expert.model.Usergroupinfo b left join Userinfo a where a.id=b.userinfooid
试试