jpql

I translated a working (postgre)sql query to jpql, but hibernate throws a org.hibernate.hql.ast.QuerySyntaxException: unexpected AST node exception These are my core model classes: @Entity public class Piece { @Id @GeneratedValue public Long id; @ManyToOne public AUser user; public long index; ... } @Entity public class Vote { @Id @GeneratedValue public Long id; @ManyToOne public AUser receiver; ... } @Entity public class AUser { @Id @GeneratedValue public Long id; @OneToMany(mappedBy="receiver", cascade=CascadeType.ALL) public List<Vote> receivedVotes; ... } Here is my jpql query: String

Is it possible to perform date arithmetic using JPA/Hibernate? For example, I have an entity with a java.util.Date field indicating when the row was created. Is it possible to perform a query using JPQL and include date arithmetic on that field? For example, can I perform a COUNT(*) of rows and then GROUP BY the month in that field? Can I perform other functions, such as only return the month or year from that field in a query? HQL does have date expressions like second(...) , minute(...) , hour(...) , day(...) , month(...) , and year(...) but standard JPQL doesn't have such functions. 来源：

I am having problem with building a query with JPA Criteria API. Entities and significant properties: @Entity public class Post { @Id int id; @OneToMany (mappedBy = "post") Set<Comment> comments; //... } @Entity public class Comment { @Id int id; @ManyToOne Post post; //... } I need a query that will return all posts from db ordered by number of comments ( OneToMany in Post ). At first I thought this can be implemented with JPQL like: SELECT p FROM Post p ORDER BY SIZE(p.comments) DESC But function SIZE(...) can not be used to be ordered by it in JPQL . So, I found about JPA Criteria API , and

I’m using JPA 2.1, Hibernate 4.3.6.Final, and MySQL 5.5.37. How do I write a JPQL query that does a join? I’m trying below final String jpqlQuery = "SELECT m FROM Message m LEFT JOIN MessageReadDate mr " + " INNER JOIN m.group g " + " LEFT JOIN g.classroom c " + " LEFT JOIN c.ROSTER u WHERE " + " u.USER = :recipient AND " + " u.ENABLED = 1 AND " + " c.ENABLED = 1 AND " + " g.NAME = '' AND " + " m.author <> :author"; Query query = m_entityManager.createQuery(jpqlQuery); but getting the error “Path expected for join! … Invalid path: 'g.classroom'”. org.hibernate.hql.internal.ast.ErrorCounter -

I am using JPQL for the model queries from Play Framework. I wonder if JPQL supports "complex" ON condition for LEFT JOIN. In an example I have, there are 2 tables: 'App' - list of applications 'AggregationHistory' - the list of the aggregation records per application, per date. In the model, it has 'app' field representing many-to-one with 'App' (column name 'app_id' in the physical table) Suppose I want to calculate the list of all the apps that do not have a record for a specific date. In plain SQL, I get the result using the following query: SELECT a.* FROM app a LEFT JOIN