Question

我遇到与criteriaquery用法相关的问题。这是我的代码

    VetPreferredLocation[] preffLoc = null;
    Predicate p1 = null;
    CriteriaBuilder builder = entityManager.getCriteriaBuilder();
    CriteriaQuery<Vet> criteriaQuery = builder.createQuery(Vet.class);
    Root<Vet> root = criteriaQuery.from(Vet.class);
    if (vet.getVetPreferredLocations() != null) {
        preffLoc = vet.getVetPreferredLocations().toArray(new VetPreferredLocation[0]);
        if (preffLoc != null && preffLoc[0].getZipcode() != null) {
            p1 = builder.like(/*companyRoot.join("products").get("category")*/
                    root.get("vetPreferredLocations").get("zipcode"), preffLoc[0].getZipcode());
        }
    }
    if (p1 != null) {
        criteriaQuery.multiselect(root.get("qualification"), 
                builder.concat(root.get("user").get("firstName") + " ", root.get("user").get("lastName")), 
                root.get("hospitals").get("name"),
                builder.avg(root.get("ratings").get("rating"))).where(p1);
    }
    List<Vet> vets = null;
    try {
        vets = entityManager.createQuery(criteriaQuery).getResultList();
    } catch (Exception e) {

    }
    return vets;

我在这里检索基于过滤器的实体。为此，我创建了一个Predicate对象。

这是实体

private static final long serialVersionUID = 1L;

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

@OneToMany//(mappedBy = "vet")
private Set<VetPreferredLocation> vetPreferredLocations = new HashSet<>();



public Set<VetPreferredLocation> getVetPreferredLocations() {
    return vetPreferredLocations;
}

public void setVetPreferredLocations(Set<VetPreferredLocation> vetPreferredLocations) {
    this.vetPreferredLocations = vetPreferredLocations;
}

**未添加完整的成员集，getter setter，constructers等这是已加入的实体

      @Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

@Column(name = "zipcode")
private String zipcode;

@Column(name = "locality")
private String locality;

@Column(name = "longitude")
private Float longitude;

@Column(name = "lattitude")
private Float lattitude;

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "vet_id")
private Vet vet;

**适当的吸气剂设定者等

执行root.get("vetPreferredLocations").get("zipcode")时，我收到以下异常

Caused by: java.lang.IllegalStateException: Illegal attempt to dereference path source [null.vetPreferredLocations] of basic type

如果我将root.get（）更改为root.join（），则会发生异常，但生成的查询具有错误的表名，即vet_preferred_location而不是vet_vet_preferred_location，我看到git tag -l | xargs git tag -d && git fetch -t。这给出了一个未找到的表异常..

请发表你的建议，如果有的话......

JPA CiteriaQuery连接在查询

0 个答案: