休眠条件无法检索联接的值

Question

I have following entities and need to retrieve a list of names of all stores that are in a specific group and have branches in a specific city. Majority of tutorials and articles that Ive found are related to creating this type of relationships but none of them is about retrieval!

I changed the criteria for many times but Hibernate shows different errors for each. The commented parts of the code are those that I tried and the respective thrown exception is also written in front of each.

Entities

@Entity
public class Store {
    @Id
    String id;
    String name;
    @JoinTable(name = "store_groups", joinColumns = { @JoinColumn(name = "id", nullable = false, updatable = false) }, inverseJoinColumns = { @JoinColumn(name = "code", nullable = false, updatable = false) })
    private Set<Group> groups = new HashSet<Group>(0);
    private Set<StoreAddress> storeAddresses = new HashSet<StoreAddress>(0);
   ....
}



@Entity
public class Group {
    @Id
    String code;
    @Column(nullable = false, unique = true)
    String name;
    @ManyToMany(fetch = FetchType.LAZY, mappedBy = "groups")
    Set<Store> storees = new HashSet<Store>(0);

}


@Entity
@Table(name = "StoreAddresses")
@AssociationOverrides({
        @AssociationOverride(name = "muJoinTable.store", joinColumns = @JoinColumn(name = "id", nullable = false)),
        @AssociationOverride(name = "myJoinTable.city", joinColumns = @JoinColumn(name = "cityCode", nullable = false)) })
public class StoreAddress {
    @EmbeddedId
    private StoreCitysId myJoinTable = new StoreCitysId();
        ...

}


@Embeddable
public class StoreCitysId {
    @ManyToOne
    private Store store;
    @ManyToOne
    private City city;
}

@Entity
public class City {
    @Id
    short code;
    @Column(nullable = false)
    String name;
        @OneToMany(fetch = FetchType.LAZY, mappedBy = "myJoinTable.city")
    private Set<StoreAddress> storeAddresses = new HashSet<StoreAddress>(
            0);
}

Criteria

        List<String> storees = (List<String>) sessionFactory
                .getCurrentSession()
                .createCriteria(Store.class)
                .setProjection(
                        Projections.property("name").as(
                                "storeName"))
                .createAlias("groups", "group")
                .createAlias("storeAddresses", "address")
                // .createAlias("address.myJoinTable.city", "city")

//              .createAlias("address.myJoinTable", "myJoinTable")
//              .createAlias("myJoinTable.city", "city") Error: Criteria objects cannot be created directly on components


                .setFetchMode("group", FetchMode.JOIN)
                .add(Restrictions.ilike("group.code", store))
                .add(Restrictions.eq("address.myJoinTable.cityCode",
                        1)).list(); //city.code -> Error: could not resolve property: cityCode of:com.example.entity.StoreAddress  address.myJoinTable.cityCode could not resolve property: myJoinTable.cityCode of:com.example.entity.StoreAddress

Answer 1

Your criterion Restrictions.eq("address.myJoinTable.cityCode", 1) doesn't reference a property but the name of the column. You could instead use address.myJoinTable.city and set the value to session.load(City.class, 1) making Restrictions.eq("address.myJoinTable.city", session.load(City.class, 1))

And this:

.createAlias("address.myJoinTable", "myJoinTable")
.createAlias("myJoinTable.city", "city")

Should be:

.createAlias("address.myJoinTable.city", "city")