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当与另一个对象存在多对多关系时，我在删除内容时遇到了一些麻烦。

要执行删除，我有一个命名查询数组并要删除，我遍历数组并执行删除，每个实体的实体，如下所示：

private static final String[] DELETE_CONTENT_QUERY_NAMES = {
    "Entity1.deleteByContentId",
    "Entity2.deleteByContentId",
    "Entity3.deleteByContentId",
    "Entity4.deleteByContentId",
    "Entity5.deleteByContentId",
    "EntityWithManyToMany.deleteByContentId",
    "Entity7.deleteByContentId",
    "Content.DeleteByContent"
}; 

@Override
@Transactional
public void deleteContent(Content content) throws Exception{
    Map<String, Object> params = new HashMap<String, Object>();
    params.put("contentId", content.getContentId());
    for (String queryName : DELETE_CONTENT_QUERY_NAMES) {
        dao.batchDeleteByNamedQuery(queryName, params);
    }
}

当迭代尝试执行EntityWithManyToMany.deleteByContentId HQL 批量查询时，我可以在日志上看到翻译后的 sql 指令，但后面跟着一组同一行的插入，MySQL 正确地返回了一个约束错误。

这是我尝试删除的多对多关系对象：

@Entity
@Embeddable
public class CategoryContent implements java.io.Serializable {

    /***
     *  Private Declarations
     */
    @EmbeddedId
    @AttributeOverrides({
         @AttributeOverride(name = "contentId", column = @Column(
                name = "CONTENT_ID", 
                nullable = false, precision = 10, scale = 0)), 
         @AttributeOverride(name = "categoryId", column = @Column(
                name = "CATEGORY_ID",
                nullable = false, precision = 10, scale = 0))
    })
    @NotNull
    private CategoryContentId id;

    @ManyToOne(fetch = FetchType.EAGER, cascade=CascadeType.PERSIST)
    @JoinColumn(name = "CATEGORY_ID", insertable=false, updatable=false)
    private Category category;

    @ManyToOne(fetch = FetchType.EAGER, cascade=CascadeType.PERSIST)
    @JoinColumn(name = "CONTENT_ID", insertable=false, updatable=false)
    private Content content;

    @Column(name = "PRIORITY", nullable = true)
    private Integer priority;
}

您认为问题可能与 CascadeType 有关吗？我该如何解决这个问题？

任何建议表示赞赏！

非常感谢，戴维德。

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1 回答 1

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您走在正确的轨道上-尝试将级联修改为

cascade = {CascadeType.PERSIST, CascadeType.DELETE}

这应该有效，因为您有一个 Join 表。

于 2011-10-31T15:58:31.293 回答