Question

我对使用MapJoin的条件计数查询有疑问！事实上它不起作用！

这是我的代码：

public long countItems(final String title, final String url) {
    CriteriaBuilder builder = entityManager.getCriteriaBuilder();
    CriteriaQuery<CmsItem> query = builder.createQuery(entityClass);
    Root<CmsItem> page = query.from(entityClass);
    query.select(page);
    MapJoin<Map<Lang, CmsItemLang>, Lang, CmsItemLang> mapJoin = page
            .joinMap("cmsItemLang");

    List<Predicate> predicateList = new ArrayList<Predicate>();
    Predicate titlePredicate, urlPredicate;
    if ((title != null) && (!(title.isEmpty()))) {
        titlePredicate = builder.like(
                builder.upper(mapJoin.value().<String> get("metaTitle")),
                "%" + title.toUpperCase() + "%");
        predicateList.add(titlePredicate);
    }
    if ((url != null) && (!(url.isEmpty()))) {
        urlPredicate = builder.like(
                builder.upper(mapJoin.value().<String> get("linkRewrite")),
                "%" + url.toUpperCase() + "%");
        predicateList.add(urlPredicate);
    }

    Predicate[] predicates = new Predicate[predicateList.size()];
    predicateList.toArray(predicates);
    query.where(predicates).distinct(true);

    CriteriaQuery<Long> cq = builder.createQuery(Long.class);
    cq.select(builder.count(cq.from(entityClass)));
    entityManager.createQuery(cq);
    cq.where(predicates);
    Long count = entityManager.createQuery(cq).getSingleResult();

    return count;
}

当我调用方法url param或title param不为null时，我有这个错误：

org.hibernate.QueryException: could not resolve property: linkRewrite of: com.demkocompany.models.CmsItem [select count(*) from com.demkocompany.models.CmsItem as generatedAlias0 where upper(generatedAlias0.linkRewrite) like :param0]

这是我的实体：

public class CmsItem {

@Id
@Column(name = "id", unique = true, nullable = false)
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;


@OneToMany(cascade = { CascadeType.PERSIST, CascadeType.MERGE,
        CascadeType.REMOVE }, fetch = FetchType.EAGER, mappedBy = "cmsItemLangPK.item")
@MapKey(name = "cmsItemLangPK.lang")
private Map<Lang, CmsItemLang> cmsItemLang;



public CmsItem() {
}


public Integer getId() {
    return this.id;
}

public void setId(Integer id) {
    this.id = id;
}


public Map<Lang, CmsItemLang> getCmsItemLang() {
    return cmsItemLang;
}

public void setCmsItemLang(Map<Lang, CmsItemLang> cmsItemLang) {
    this.cmsItemLang = cmsItemLang;
}


}

和第二个实体（对于地图）

public class CmsItemLang implements Serializable {

private static final long serialVersionUID = 6832580916240288447L;

@EmbeddedId
private CmsItemLangPK cmsItemLangPK;

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

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

@Lob
@Column(name = "text")
private String text;

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

@Column(name = "meta_title", length = 128)
private String metaTitle;

@Column(name = "meta_keywords", length = 255)
private String metaKeywords;

@Column(name = "meta_description", length = 255)
private String metaDescription;

public CmsItemLang() {
}

public CmsItemLangPK getCmsItemLangPK() {
    return cmsItemLangPK;
}

public void setCmsItemLangPK(CmsItemLangPK cmsItemLangPK) {
    this.cmsItemLangPK = cmsItemLangPK;
}

public String getTitle() {
    return title;
}

public void setTitle(String title) {
    this.title = title;
}

public String getDescription() {
    return description;
}

public void setDescription(String description) {
    this.description = description;
}

public String getText() {
    return text;
}

public void setText(String text) {
    this.text = text;
}

public String getLinkRewrite() {
    return linkRewrite;
}

public void setLinkRewrite(String linkRewrite) {
    this.linkRewrite = linkRewrite;
}

public String getMetaTitle() {
    return metaTitle;
}

public void setMetaTitle(String meta_title) {
    this.metaTitle = meta_title;
}

public String getMetaKeywords() {
    return metaKeywords;
}

public void setMetaKeywords(String meta_keywords) {
    this.metaKeywords = meta_keywords;
}

public String getMetaDescription() {
    return metaDescription;
}

public void setMetaDescription(String meta_description) {
    this.metaDescription = meta_description;
}

}

当我尝试这样做时，我不明白为什么会出现这个错误... 因为没有计数（在其他方法中找到项目）它运作良好... 但要计算搜索的所有结果......请求是错误的......

有人可以帮我纠正这个问题吗？

非常感谢

Answer 1

该错误可能是由于类com.demkocompany.models.CmsItem没有linkRewrite属性。仔细检查你是否拥有它，并且可访问性必须公开（我认为）

  public String getLinkRewrite() {
    // ...
  }

  public void setLinkRewrite(String linkRewrite) {
    // ...
  }

JPA：在MapJoin上使用谓词计算

1 个答案: