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http://opensource.atlassian.com/projects/hibernate/browse/HHH-817?page=co...
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David commented on HHH-817:
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this bug is especially potent because it's the recommended technique for avoiding
lazy-loaded properties!
http://www.hibernate.org/hib_docs/reference/en/html/performance.html
" A different (better?) way to avoid unnecessary column reads, at least for read-only
transactions is to use the projection features of HQL or Criteria queries. This avoids the
need for buildtime bytecode processing and is certainly a preferred solution. "
If lazy-loading is the most requested feature, like the documentation says, and if people
are expected to use the ProjectionList behavior in criteria searches to avoid loading
their blobs, etc... It's crazy this hasn't been fixed. For everything that
hibernate does, I'm really surprised someone hasn't addressed this massively basic
use case. I shouldn't have to create two tables and two classes because of one simple
column.
Aggregate projection aliases should not be applied to where-clause
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Key: HHH-817
URL:
http://opensource.atlassian.com/projects/hibernate/browse/HHH-817
Project: Hibernate Core
Issue Type: Bug
Components: core
Affects Versions: 3.0.5
Environment: Oracle 9.2.0.6, Hibernate 3.0.5, Spring Framework 1.2.2 based
application working on Jakarta Tomcat 5.0.28
Reporter: Michal Jastak
Priority: Minor
Attachments: HHH-817.patch
following java code:
protected Entity loadEntityLightweight(Serializable entityId) throws DataAccessException
{
Criteria criteria = getSession().createCriteria(Entity.class);
ProjectionList projectionList = Projections.projectionList();
projectionList.add(Property.forName(BaseEntity.PROP_ID), BaseEntity.PROP_ID);
projectionList.add(Property.forName(BaseEntity.PROP_TYPE), BaseEntity.PROP_TYPE);
criteria.setProjection(projectionList);
criteria.add(Restrictions.eq(BaseEntity.PROP_ID, entityId));
criteria.setResultTransformer(new AliasToBeanResultTransformer(Entity.class));
return (Entity) criteria.uniqueResult();
}
generates following SQL query:
select this_.id as y0_, this_.type as y1_ from entities this_ left outer join facilities
this_1_ on this_.id=this_1_.id left outer join users this_2_ on this_.id=this_2_.id left
outer join addresses address2_ on this_.address_id=address2_.id left outer join entities
entity3_ on this_2_.employer_id=entity3_.id left outer join facilities entity3_1_ on
entity3_.id=entity3_1_.id left outer join users entity3_2_ on entity3_.id=entity3_2_.id
where y0_=?
y0_ = ? expression in where clause is causing a 904 error on Oracle 9:
ORA-00904: "Y0_": invalid identifier
hibernate dialect: org.hibernate.dialect.Oracle9Dialect
mapping for Entity class:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD
3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping default-lazy="false"
default-cascade="save-update">
<class name="Entity" table="entities"
mutable="true">
<id name="id" type="java.lang.Long"
unsaved-value="null">
<generator class="sequence">
<param name="sequence">entities_id_seq</param>
</generator>
</id>
<many-to-one name="address" class="Address"
column="address_id" />
...
<!--
- Facilities
-->
<joined-subclass name="Facility" table="facilities">
<key column="id" />
...
<set name="users" inverse="true" lazy="true">
<key column="facility_id" />
<one-to-many class="User" />
</set>
</joined-subclass>
<!--
- Users
-->
<joined-subclass name="User" table="users"
dynamic-insert="true" dynamic-update="true">
<key column="id" />
<many-to-one name="employer" class="Entity"
column="employer_id" cascade="none" />
...
<set name="userAuthorities" inverse="true"
cascade="all-delete-orphan">
<key column="user_id" />
<one-to-many class="Authority" />
</set>
</joined-subclass>
</class>
</hibernate-mapping>
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