HQL against collection of composite elements

ollie · **Joined:** Fri Dec 05, 2003 12:44 am **Posts:** 16

I'm having trouble working out how to write a query where I need to select against a value in a collection of composite elements.

This is the mapping:

Code:

<?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="ourcommunity.article.dao.ArticleDO" table="Article">
        <cache usage="read-write" /> 
    
        <id name="id" type="int" column="ID" unsaved-value="0" >
            <generator class="identity"/>
        </id>
        
        <version name="version" type="long" />

        <property name="enabled" />
        
        <set name="categories" table="ArticleCategory" cascade="all">
            <cache usage="read-write" /> 
            <key column="OrgID"/>
            <composite-element class="ourcommunity.category.dao.WeightedCategoryDO">
                <property name="weight" />
                <property name="categoryId" />
            </composite-element>
        </set>          
    </class>
</hibernate-mapping>

and this is the query I tried:

Code:

SELECT 
  a 
FROM 
  ourcommunity.article.dao.ArticleDO a, 
  ourcommunity.category.dao.WeightedCategoryDO ac 
WHERE 
  a.enabled=1 
AND ac in elements(a.categories) 
AND ac.categoryId=?

But when I run the query to SQL get sent to the DB and this message in the logs:

Code:

WARN  [QueryTranslator] no persistent classes found for query class: SELECT a FROM ourcommunity.article.dao.ArticleDO a, ourcommunity.category.dao.WeightedCategoryDO ac WHERE a.enabled=1 AND ac in elements(a.categories) AND ac.categoryId=?

What is the correct way to do this query in HQL? Or do I have to do an SQL query?

Thanks

emmanuel · **Posted:** Fri Dec 12, 2003 7:12 am

Use Hibernate 2.1, component cannot be queried in 2.0.x
You cannot request directly a composite element (can't be in the from clause)
Try to join with another ArticleDO

emmanuel · **Posted:** Fri Dec 12, 2003 7:18 am

Try

Code:

SELECT
  a
FROM
  ourcommunity.article.dao.ArticleDO a
WHERE
  a.enabled=1
AND a.categories.categoryId=? 

ollie · **Joined:** Fri Dec 05, 2003 12:44 am **Posts:** 16

I'm using Hibernate 2.1 rc1 and this does not work... I get the folowing exception:

Code:

net.sf.hibernate.QueryException: expecting 'elements' or 'indices' after: categoryId [SELECT a FROM ourcommunity.article.dao.ArticleDO a WHERE a.enabled=1 AND a.categories.categoryId=?]
        at net.sf.hibernate.collection.CollectionPropertyMapping.toType(CollectionPropertyMapping.java:53)
        at net.sf.hibernate.hql.PathExpressionParser.getPropertyType(PathExpressionParser.java:244)
        at net.sf.hibernate.hql.PathExpressionParser.end(PathExpressionParser.java:283)
        at net.sf.hibernate.hql.WhereParser.doPathExpression(WhereParser.java:336)
        at net.sf.hibernate.hql.WhereParser.doToken(WhereParser.java:366)
        at net.sf.hibernate.hql.WhereParser.token(WhereParser.java:251)
        at net.sf.hibernate.hql.ClauseParser.token(ClauseParser.java:87)
        at net.sf.hibernate.hql.PreprocessingParser.token(PreprocessingParser.java:123)
        at net.sf.hibernate.hql.ParserHelper.parse(ParserHelper.java:29)
        at net.sf.hibernate.hql.QueryTranslator.compile(QueryTranslator.java:152)
        at net.sf.hibernate.hql.QueryTranslator.compile(QueryTranslator.java:141)
        at net.sf.hibernate.impl.SessionFactoryImpl.getQuery(SessionFactoryImpl.java:287)
        at net.sf.hibernate.impl.SessionImpl.getQueries(SessionImpl.java:1488)
        at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1459)
        at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1449)
        at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1445)
        at ourcommunity.util.hibernate.HibernateHelper.find(HibernateHelper.java:303)
        at ourcommunity.article.dao.ArticleDAO.findArticlesByCategoryId(ArticleDAO.java:47)
        at ourcommunity.article.dao.ArticleDAO.main(ArticleDAO.java:79)

gavin · **Posted:** Sun Dec 14, 2003 8:57 pm

Nope, navigating through a multi-valued property does not work in Java either. The correct syntax is:

Code:

select a
from ArticleDO a 
join a.categories  cat
where a.enabled=1 and cat.categoryId=?