If you want to use your custom function in HQL, you’ll need to define it in appropriate Dialect Take a look at PostgreSQLDialect (or any other, really) source, and you’ll see a bunch of registerFunction() calls. You’ll need to add one more 🙂 – for your own custom function. You’ll then have to specify your … Read more
Here’s a snippet of hql that we use. (Names have been changed to protect identities) String queryString = “select distinct f from Foo f inner join foo.bars as b” + ” where f.creationDate >= ? and f.creationDate < ? and b.bar = ?”; return getHibernateTemplate().find(queryString, new Object[] {startDate, endDate, bar});
This is indeed possible with criteria: DetachedCriteria ownerCriteria = DetachedCriteria.forClass(Owner.class); ownerCriteria.setProjection(Property.forName(“id”)); ownerCriteria.add(Restrictions.eq(“ownername”, “bob”)); Criteria criteria = getSession().createCriteria(Pet.class); criteria.add(Property.forName(“ownerId”).in(ownerCriteria)); Update: This actually performs a sub-query instead of a join but it allows you to use Criteria on two entities that do not have a hibernate relationship defined.
I mostly prefer Criteria Queries for dynamic queries. For example it is much easier to add some ordering dynamically or leave some parts (e.g. restrictions) out depending on some parameter. On the other hand I’m using HQL for static and complex queries, because it’s much easier to understand/read HQL. Also, HQL is a bit more … Read more
In this two queries, you are using JOIN to query all employees that have at least one department associated. But, the difference is: in the first query you are returning only the Employes for the Hibernate. In the second query, you are returning the Employes and all Departments associated. So, if you use the second … Read more
This was posted on the Hibernate forum a few years back when asked about why this worked in Hibernate 2 but not in Hibernate 3: Limit was never a supported clause in HQL. You are meant to use setMaxResults(). So if it worked in Hibernate 2, it seems that was by coincidence, rather than by … Read more