JPA 引入的 CriteriaUpdate 怎么用？

Question

问题：JPA 引入的 CriteriaUpdate 怎么用？

我的实体类

/**
 * 文章 类
 *
 * @author LJM
 */
@Data
@Entity
@NoArgsConstructor
@AllArgsConstructor
@Table(name = "ARTICLE")
public class Article {

    /**
     * 文章 id
     */
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "article_id", nullable = false)
    private Long articleId;

    /**
     * 文章 标题
     */
    @Column(name = "article_title")
    private String articleTitle;

    /**
     * 文章 内容
     */
    @Column(name = "article_content")
    private String articleContent;

    /**
     * 文章 类型
     */
    @Column(name = "article_type")
    private String articleType;

    /**
     * 文章 阅读量
     */
    @Column(name = "article_read_number")
    private Integer articleReadNumber;

    /**
     * 文章 点赞数
     */
    @Column(name = "article_likes_number")
    private Integer articleLikesNumber;


    /**
     * 多对一
     * 多方
     * 作者外键
     * 维护方
     */
    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "article_author_id")
    private Author author;

    public Article(Long articleId, String articleType) {
        this.articleId = articleId;
        this.articleType = articleType;
    }


    public Article(Long articleId, String articleContent, String articleType, Integer articleReadNumber) {
        this.articleId = articleId;
        this.articleContent = articleContent;
        this.articleType = articleType;
        this.articleReadNumber = articleReadNumber;
    }

//    public Article(Long articleId, String articleContent, String articleType, Integer articleReadNumber, Integer articleLikesNumber) {
//        this.articleId = articleId;
//        this.articleContent = articleContent;
//        this.articleType = articleType;
//        this.articleReadNumber = articleReadNumber;
//        this.articleLikesNumber = articleLikesNumber;
//    }


    public Article(Long articleId, String articleTitle, String articleContent, String articleType, Integer articleReadNumber, Integer articleLikesNumber) {
        this.articleId = articleId;
        this.articleTitle = articleTitle;
        this.articleContent = articleContent;
        this.articleType = articleType;
        this.articleReadNumber = articleReadNumber;
        this.articleLikesNumber = articleLikesNumber;
    }

    public Article(Long articleId, String articleTitle, Author author) {
        this.articleId = articleId;
        this.articleTitle = articleTitle;
        this.author = author;
    }

    public Article(Long articleId, String articleContent, String articleType, Integer articleReadNumber, Author author) {
        this.articleId = articleId;
        this.articleContent = articleContent;
        this.articleType = articleType;
        this.articleReadNumber = articleReadNumber;
        this.author = author;
    }

}

下面是我的代码

@SpringBootTest
public class text1 {
   
    @Resource
    private EntityManager entityManager;

    @Test
    public void aVoid10() {
        // 获取 条件构造器
        CriteriaBuilder builder = entityManager.getCriteriaBuilder();
        // 获取 更新条件 类
        CriteriaUpdate
 criteriaUpdate = builder.createCriteriaUpdate(Article.class);
        // 指定查询的实体类
        //  即：UPDATE article
        Root
 root = criteriaUpdate.from(Article.class);

        // 开始构建更新语句
        criteriaUpdate
                // 添加更新内容 即：SET
                .set(root.get("articleTitle"),"更新测试")
                .set(root.get("articleContent"), "更新")
                // 添加 条件 WHERE
                .where(
                        builder.equal(root.get("articleId"), 9L)
                );
        // 创建 一个 Query的实例 用于执行 条件更新。
        Query query = entityManager.createQuery(criteriaUpdate);
        // int i = query.executeUpdate();
        List articleList = query.getResultList();
        // System.out.println(i <= 0 ? "失败！" : "成功！");
        System.out.println("count = " + articleList.size());
        System.out.println(articleList);
        System.out.println("query = " + ResultVO.success(articleList));
    }

}

使用 query.getResultList() 时，错误如下

java.lang.IllegalStateException: org.hibernate.hql.internal.QueryExecutionRequestException: Not supported for DML operations [update com.example.demo.entity.Article as generatedAlias0 set generatedAlias0.articleTitle = :param0, generatedAlias0.articleContent = :param1 where generatedAlias0.articleId=9L]

    at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1620)
    at org.hibernate.query.Query.getResultList(Query.java:165)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)

使用 query.executeUpdate() 时，错误如下

javax.persistence.TransactionRequiredException: Executing an update/delete query

    at org.hibernate.internal.AbstractSharedSessionContract.checkTransactionNeededForUpdateOperation(AbstractSharedSessionContract.java:445)
    at org.hibernate.query.internal.AbstractProducedQuery.executeUpdate(AbstractProducedQuery.java:1692)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)

我想要的结果

控制台输出：

Hibernate: UPDATE article SET article_title = ?, article_content = ? WHERE article_id = ?

Answer 1

参考

Hibernate ORM 5.4.33.Final User Guide https://docs.jboss.org/hibernate/orm/5.4/userguide/html_single/Hibernate_User_Guide.html#transactions-api

@SpringBootTest
public class text1 {
   
    @Autowired
    private EntityManagerFactory emf;
 
    @Test
    public void aVoid10() {
        EntityManager entityManager = emf.createEntityManager();
        entityManager.getTransaction().begin();
        // 获取 条件构造器
        CriteriaBuilder builder = entityManager.getCriteriaBuilder();
        // 获取 更新条件 类
        CriteriaUpdate
 criteriaUpdate = builder.createCriteriaUpdate(Article.class);
        // 指定查询的实体类
        //  即：UPDATE article
        Root
 root = criteriaUpdate.from(Article.class);
 
        // 开始构建更新语句
        criteriaUpdate
                // 添加更新内容 即：SET
                .set(root.get("articleTitle"),"更新测试")
                .set(root.get("articleContent"), "更新")
                // 添加 条件 WHERE
                .where(
                        builder.equal(root.get("articleId"), 9L)
                );
        // 创建 一个 Query的实例 用于执行 条件更新。
        Query query = entityManager.createQuery(criteriaUpdate);
        int i = query.executeUpdate();
        entityManager.getTransaction().commit();
    }
 
}