Hi,
I'm trying to get a simple query working whith the Criteria API on Hibernate 3.0.5 but I just can't make it work.

MailBox 1----* Folder 1----- * Mail

The HSQL Query working is :
select count(mail) from mail where mail.folder.mailBox.id = '1'

But when I write the same request whith the Criteria API :

Criteria crit = session.createCriteria(Mail.class);
crit.add(Expression.eq("mail.folder.mailBox", "1"));
crit.setProjection(Projections.count("id").as("result"));
crit.list();

I've got an Exception

org.hibernate.QueryException: could not resolve property: folder.mailBox.id of: Mail
at org.hibernate.persister.entity.AbstractPropertyMapping.throwPropertyException(AbstractPropertyMapping.java:43)
at org.hibernate.persister.entity.AbstractPropertyMapping.toColumns(AbstractPropertyMapping.java:63)
at org.hibernate.persister.entity.BasicEntityPropertyMapping.toColumns(BasicEntityPropertyMapping.java:31)
at org.hibernate.persister.entity.BasicEntityPersister.toColumns(BasicEntityPersister.java:1086)
at org.hibernate.loader.criteria.CriteriaQueryTranslator.getColumns(CriteriaQueryTranslator.java:403)
at org.hibernate.loader.criteria.CriteriaQueryTranslator.getColumnsUsingProjection(CriteriaQueryTranslator.java:369)
at org.hibernate.criterion.SimpleExpression.toSqlString(SimpleExpression.java:42)
at org.hibernate.loader.criteria.CriteriaQueryTranslator.getWhereCondition(CriteriaQueryTranslator.java:314)
at org.hibernate.loader.criteria.CriteriaLoader.<init>(CriteriaLoader.java:81)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1303)
at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:300)

I just can't get it so if you have any idea.

Sorry read
crit.add(Expression.eq("folder.mailBox", "1"));
instead of
crit.add(Expression.eq("mail.folder.mailBox", "1"));

Before this line, you need to create an Alias for folder.

crit.createAlias("folder","folder");

Thanks, it's working with

Criteria crit = session.createCriteria(Mail.class, "mail");
crit.createAlias("mail.folder", "folder");
crit.createAlias("folder.mailBox", "box");
crit.add(Expression.eq("box.id", id.toLong()));
crit.setProjection(Projections.count("id").as("result"));