how to return Map with HQL

by

  1. Use the select new map syntax in HQL to fetch the results of each row in a Map. Take a look at the following question, that addresses the issue: How to fetch hibernate query result as associative array of list or hashmap.
    For instance, the following HQL: select new map(perm.id as pid, perm.name as pname) from Permission perm will return a List of Maps, each one with keys “pid” and “pname”.

  2. It is not possible to map an association to a Map<String, String>. It is possible to map the key of the Map to a column with the @MapKeyColumn annotation in the association. See this question, that also addresses the issue, for an example: JPA 2.0 Hibernate @OneToMany + @MapKeyJoinColumn. Here is another example. 


@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
@JoinTable(name = "perm_cat_map", 
    joinColumns = { @JoinColumn(name = "perm_cat_id") }, 
    inverseJoinColumns = { @JoinColumn(name = "permission_id") })
@MapKeyColumn(name="permission_id")
private Map<String, Permission> permissions = new HashMap<String,Permission>(0);

More Related Contents:

  1. How do you create a Distinct query in HQL
  2. Performing Date/Time Math In HQL?
  3. Hibernate annotation or XML configuration
  4. Date operations in HQL
  5. UnsupportedOperationException: The application must supply JDBC connections
  6. New object with HQL
  7. How to simulate NVL in HQL
  8. Mapping many-to-many association table with extra column(s)
  9. Can someone explain mappedBy in JPA and Hibernate?
  10. JPA and Hibernate – Criteria vs. JPQL or HQL
  11. What is the difference between DAO and Repository patterns?
  12. How to query data for Primefaces dataTable using lazy loading and pagination
  13. Hibernate Search: How to use wildcards correctly?
  14. Postgresql UUID supported by Hibernate?
  15. Spring Boot & Spring Data: how are Hibernate Sessions managed?
  16. Hibernate – why use many-to-one to represent a one-to-one?
  17. Using JPA entities in JSF. Which is the best strategy to prevent LazyInitializationException?
  18. Hibernate field naming issue with Spring Boot (naming strategy)
  19. Hibernate use of PostgreSQL sequence does not affect sequence table
  20. Hibernate: How specify custom sequence generator class name using annotations?
  21. Deleted object would be re-saved by cascade (remove deleted object from associations)
  22. what is the right path to refer a jar file in jpa persistence.xml in a web app?
  23. JPA CriteriaBuilder – How to use “IN” comparison operator
  24. Setting properties programmatically in Hibernate
  25. When to Use EntityManager.clear()?
  26. HQL left join of un-related entities
  27. Hibernate validator: @Email accepts ask@stackoverflow as valid?
  28. Is there a more efficient way of making pagination in Hibernate than executing select and count queries?
  29. Persist java.time.Instant (JDK8) with JPA2/Hibernate
  30. How do I map a BigDecimal in Hibernate so I get back the same scale I put in?

Leave a Comment