We started developing a medium web application (appr. 30k LOC) with hibernate about 9 months ago.

in the beginning we struggled quite a bit and had some problems with synchronizing objects between sessions, mapping stuff and so on. but after some time we really started loving hibernate and i think we accumulated quite a bit of knowledge and best practices in this area.

about 2 days ago i realized, that there's a new version out and downloaded it. after i installed it our application suddenly started throwing ClassCastExceptions. we had a look into it and i found out, that hibernate sometimes seems not to translate queries properly anymore.

for a simple

'select user from User as user'

the following sql statement is generated

'select user as x0_0_ from tbUser user0_ inner join tbActor user0__1_ on user0_.userActorID=user0__1_.actorID'

which returns a List of Strings instead of Users.

The mapping is as follows

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
<class name="de.sag.qsee.masterdata.data.Actor" table="tbActor">
<!-- config -->
<cache usage="read-write"/>
<!-- PK -->
<id name="actorID" column="actorID" type="int" unsaved-value="0">
<generator class="identity"/>
</id>
<!-- subclasses -->
<!-- User class -->
<joined-subclass name="de.sag.qsee.masterdata.userdata.data.User" table="tbUser">
<key column="userActorID"/>
<property name="status" column="status" type="int"/>
<property name="lastName" column="lastName" type="string"/>
<property name="firstName" column="firstName" type="string"/>
<property name="userName" column="userName" type="string"/>
<property name="loginName" column="loginName" type="string"/>
<property name="password" column="password" type="string"/>
<property name="numberFailedLogins" column="numberFailedLogins" type="int"/>
<property name="phone" column="phone" type="string"/>
<property name="fax" column="fax" type="string"/>
<property name="electronicMail" column="electronicMail" type="string"/>
<property name="isSalesAmiabilityOriginator" column="isSalesAmiabilityOriginator" type="boolean"/>
<property name="salesAmiabilityNo" column="salesAmiabilityNo" type="string"/>
<many-to-one name="language" column="languageID" not-null="true"/>
<many-to-one name="country" column="countryID" not-null="true"/>
<many-to-one name="currentRole" column="currentRole" not-null="false"/>
<bag name="roles" table="tbUser2Role" lazy="true">
<key column="userActorID"/>
<many-to-many class="de.sag.qsee.masterdata.userdata.data.Role" column="tbRoleID"/>
</bag>
<!-- subclasses -->
<!-- Technician class -->
<joined-subclass name="de.sag.qsee.masterdata.userdata.data.Technician" table="tbTechnician">
<key column="technicianActorID"/>
<!-- local attributes -->
<property name="technicianNo" column="technicianNo" type="string"/>
<property name="shortMark" column="shortMark" type="string"/>
<property name="mobilePhone" column="mobilePhone" type="string"/>
<property name="birthday" column="birthday" type="date"/>
<property name="collectionAccount" column="collectionAccount" type="string"/>
<property name="carNumber" column="carNumber" type="string"/>
<!-- one to many -->
<bag name="repairTypes" table="tbTechnicianQualification" lazy="true">
<key column="technicianActorID"/>
<many-to-many class="de.sag.qsee.masterdata.oemdata.data.RepairType" column="tbRepairTypeID"/>
</bag>
<bag name="addresses" table="tbAddress" inverse="true" lazy="true" cascade="all">
<key column="actorID"/>
<one-to-many class="de.sag.qsee.masterdata.data.Address"/>
</bag>
<bag name="workingDays" table="tbTechnicianWorkingDays" inverse="true" lazy="true">
<key column="technicianActorID"/>
<one-to-many class="de.sag.qsee.masterdata.userdata.data.TechnicianWorkingDay"/>
</bag>
<bag name="appointments" table="tbTechnicianAppointmentSlots" inverse="true" lazy="true">
<key column="technicianActorID"/>
<one-to-many class="de.sag.qsee.taskscheduler.data.TechnicianAppointmentSlot"/>
</bag>
</joined-subclass>
</joined-subclass>
</class>
</hibernate-mapping>


The strange thing about it is, if i do the same for Technicians, which is a subclass of User, it works fine.

Any ideas?

"user" in the select clause is now a recognized keyword for some databases (hsql, oracle). Just use "select uzer from User uzer". This is kind of a bug, aliases should really override sql functions.

I just realized something.

If I drop the 'select user' and write

'from User as user' instead

everything works fine.

how's that possible?

all right, that explains a lot ;-)

thx for the quick answer!