Following example shows how to navigate Map association using keywords KEY, VALUE and ENTRY in JPQL.

Example

Entities

@Entity
public class Customer {
  @Id
  @GeneratedValue
  private int id;
  private String name;
  @OneToMany(cascade = CascadeType.ALL)
  private Map<String, Order> orderMap;
    .............
}

@Entity
@Table(name="CustomerOrder")
public class Order {
  @Id
  @GeneratedValue
  private long id;
  private String item;
  private int qty;
    .............
}

Navigating map

public class ExampleMain {

  public static void main(String[] args) {
      EntityManagerFactory emf = Persistence.createEntityManagerFactory("example-unit");
      try {
          persistEntity(emf);
          findItemQty(emf);
          findOrderMapEntry(emf);
          findCustomerByItemName(emf);
      } finally {
          emf.close();
      }
  }

  private static void persistEntity(EntityManagerFactory emf) {
      System.out.println("-- Persisting entities --");
      EntityManager em = emf.createEntityManager();

      Customer c1 = new Customer();
      c1.setName("Lindsey Craft");
      c1.addOrder("online", "XYZ Blender", 2);
      c1.addOrder("store", "ZZZ Beer Glass", 4);
      System.out.println(c1);

      Customer c2 = new Customer();
      c2.setName("Morgan Philips");
      c2.addOrder("online", "AA Glass Cleaner", 3);
      System.out.println(c2);

      em.getTransaction().begin();
      em.persist(c1);
      em.persist(c2);
      em.getTransaction().commit();
      em.close();
  }

  private static void findItemQty(EntityManagerFactory emf) {
      System.out.println("-- Finding items and keys --");
      EntityManager em = emf.createEntityManager();
      TypedQuery<Tuple> query =
              em.createQuery("SELECT c.name, KEY(map), VALUE(map).item, VALUE(map).qty "
                      + "FROM Customer c JOIN c.orderMap map", Tuple.class);
      query.getResultList().forEach(
              t -> System.out.printf("Customer: %s, Order-Type: %s, Order-item: %s, Order-qty: %s%n",
                      t.get(0), t.get(1), t.get(2), t.get(3)));
  }

  private static void findOrderMapEntry(EntityManagerFactory emf) {
      System.out.println("-- Finding item/keys entries  --");
      EntityManager em = emf.createEntityManager();
      TypedQuery<Map.Entry> query =
              em.createQuery("SELECT ENTRY(c.orderMap) FROM Customer c", Map.Entry.class);
      query.getResultList().forEach(entry -> System.out.printf("Order-Type: %s, Order: %s%n",
              entry.getKey(), entry.getValue()));
  }

  private static void findCustomerByItemName(EntityManagerFactory emf) {
      System.out.println("-- Finding  customers where item name like %Beer% --");
      EntityManager em = emf.createEntityManager();
      TypedQuery<Customer> query =
              em.createQuery("SELECT c FROM Customer c"
                      + " WHERE VALUE(c.orderMap).item LIKE '%Beer%'", Customer.class);
      query.getResultList().forEach(System.out::println);
  }
}

-- Persisting entities --
Customer{id=0, name='Lindsey Craft', orderMap={online=Order{id=0, item='XYZ Blender', qty=2}, store=Order{id=0, item='ZZZ Beer Glass', qty=4}}}
Customer{id=0, name='Morgan Philips', orderMap={online=Order{id=0, item='AA Glass Cleaner', qty=3}}}
-- Finding items and keys --
Customer: Lindsey Craft, Order-Type: online, Order-item: XYZ Blender, Order-qty: 2
Customer: Lindsey Craft, Order-Type: store, Order-item: ZZZ Beer Glass, Order-qty: 4
Customer: Morgan Philips, Order-Type: online, Order-item: AA Glass Cleaner, Order-qty: 3
-- Finding item/keys entries  --
Order-Type: online, Order: Order{id=2, item='XYZ Blender', qty=2}
Order-Type: store, Order: Order{id=3, item='ZZZ Beer Glass', qty=4}
Order-Type: online, Order: Order{id=5, item='AA Glass Cleaner', qty=3}
-- Finding  customers where item name like %Beer% --
Customer{id=1, name='Lindsey Craft', orderMap={online=Order{id=2, item='XYZ Blender', qty=2}, store=Order{id=3, item='ZZZ Beer Glass', qty=4}}}

Example Project

Dependencies and Technologies Used:

• h2 1.4.197: H2 Database Engine.
• hibernate-core 5.3.5.Final: Hibernate's core ORM functionality.
  Implements javax.persistence:javax.persistence-api version 2.2
• JDK 1.8
• Maven 3.5.4