It is possible starting from the version 2.1 of JPA using the on method Join<Z, X> on(Predicate… restrictions); Here is how: Root<Order> order = cq.from(Order.class); Join<Order, Item> item = order.join(Order_.itemList, JoinType.LEFT); item.on(cb.equal(item.get(Item_.type), 1));
builder.not(root.get({field_name}).in(seqs)) seqs is collection.
You can pass an array of predicates to the CriteriaBuilder, deciding on equal or like as you go. For this, build a list and pack the contents of the list into an array in a single and statement. Like this: final List<Predicate> predicates = new ArrayList<Predicate>(); for (final Entry<String, String> e : myPredicateMap.entrySet()) { final … Read more
That is the metamodel for the persistance. It is how you can do type safe JPA queries in Java. It allows queries to staticly check your queries because classBar_ describes your JPA Bar. In HQL, you can easily mistype a query and not know it until it is run. So technically, the _ does not … Read more
Maybe the following extract from the Chapter 23 – Using the Criteria API to Create Queries of the Java EE 6 tutorial will throw some light (actually, I suggest reading the whole Chapter 23): Querying Relationships Using Joins For queries that navigate to related entity classes, the query must define a join to the related … Read more
Why not using the @Query annotation? @Query(“select p.id from #{#entityName} p”) List<Long> getAllIds(); The only disadvantage I see is when the attribute id changes, but since this is a very common name and unlikely to change (id = primary key), this should be ok.
Perhaps you need criteria.add(cb.like(emp.<String>get(“name”), p)); because first argument of like() is Expression<String>, not Expression<?> as in equal(). Another approach is to enable generation of the static metamodel (see docs of your JPA implementation) and use typesafe Criteria API: criteria.add(cb.like(emp.get(Employee_.name), p)); (Note that you can’t get static metamodel from em.getMetamodel(), you need to generate it by … Read more
The problem is that with the string-based API it cannot infer the type for the result value of the get-Operation. This is explained for example in Javadoc for Path. If you use predicates.add(builder.lessThanOrEqualTo(root.<Date>get(“dateCreated”), param)); instead, it will work fine, because it can figure out the return type from the type argument and will find out … Read more
If you need to add couple of orders you can make something like (but for your query and different root objects) CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder(); CriteriaQuery<Route> query = criteriaBuilder.createQuery(Route.class); Root<Route> routeRoot = query.from(Route.class); query.select(routeRoot); List<Order> orderList = new ArrayList(); query.where(routeRoot.get(“owner”).in(user)); orderList.add(criteriaBuilder.desc(routeRoot.get(“date”))); orderList.add(criteriaBuilder.desc(routeRoot.get(“rating”))); query.orderBy(orderList);
If I understand well, you want to Join ScheduleRequest with User and apply the in clause to the userName property of the entity User. I’d need to work a bit on this schema. But you can try with this trick, that is much more readable than the code you posted, and avoids the Join part … Read more