Hibernate @ElementCollection Map with @Audited 在更新时创建重复键冲突

Question

我在使用休眠映射和审计时遇到了问题。 我的带有映射的 java 类：

@Entiy
@Audited
@Table(name = "farm_detail")
public class FarmDetail {
   @Id
   private Long id;

    @ElementCollection
    @MapKeyColumn(name = "field_id")
    @Column(name = "remark")
    @CollectionTable(name = "farm_detail_remark", joinColumns =    @JoinColumn(name = "farm_detail_id"))
    private Map<String, String> fieldRemarks = new HashMap<>();
   // Getter, Setter, etc
}

farm_detail_remark和farm_detial_remark_aud表的sql定义：

db=# \d farm_detail_remark
          Table "public.farm_detail_remark"
     Column     |          Type          | Modifiers 
----------------+------------------------+-----------
 farm_detail_id | bigint                 | not null
 field_id       | character varying(255) | not null
 remark         | character varying      | not null
Indexes:
    "farm_detail_remark_pkey" PRIMARY KEY, btree (farm_detail_id, field_id)
Foreign-key constraints:
    "farm_detail_remark_farm_detail_id_fkey" FOREIGN KEY (farm_detail_id) REFERENCES farm_detail(id)

db=# \d farm_detail_remark_aud
        Table "public.farm_detail_remark_aud"
     Column     |          Type          | Modifiers 
----------------+------------------------+-----------
 rev            | integer                | not null
 revtype        | smallint               | 
 farm_detail_id | bigint                 | not null
 field_id       | character varying(255) | not null
 remark         | character varying      | 
Indexes:
    "farm_detail_remark_aud_pkey" PRIMARY KEY, btree (rev, farm_detail_id, field_id)
Foreign-key constraints:
    "farm_detail_remark_aud_rev_fkey" FOREIGN KEY (rev) REFERENCES revinfo(rev)

如果我想更新 fieldRemarks 集合的任何条目，我会在 farm_detail_remark_aud 表上收到重复键错误。通过打开 sql 日志，我发现 hibernate 尝试在 aud 表中插入两个条目：

Hibernate: 
    /* insert farm_detail_remark_AUD
        */ insert 
        into
            farm_detail_remark_aud
            (revtype, rev, farm_detail_id, remark, field_id) 
        values
            (?, ?, ?, ?, ?)
21:20:58.188 [main] TRACE o.h.t.d.s.BasicBinder - binding parameter [1] as [INTEGER] - [0]
21:20:58.188 [main] TRACE o.h.t.d.s.BasicBinder - binding parameter [2] as [INTEGER] - [1057]
21:20:58.188 [main] TRACE o.h.t.d.s.BasicBinder - binding parameter [3] as [BIGINT] - [110]
21:20:58.188 [main] TRACE o.h.t.d.s.BasicBinder - binding parameter [4] as [VARCHAR] - [Old remark]
21:20:58.188 [main] TRACE o.h.t.d.s.BasicBinder - binding parameter [5] as [VARCHAR] - [152]

和（这里只有参数绑定）：

21:20:58.193 [main] TRACE o.h.t.d.s.BasicBinder - binding parameter [1] as [INTEGER] - [2]
21:20:58.194 [main] TRACE o.h.t.d.s.BasicBinder - binding parameter [2] as [INTEGER] - [1057]
21:20:58.194 [main] TRACE o.h.t.d.s.BasicBinder - binding parameter [3] as [BIGINT] - [110]
21:20:58.194 [main] TRACE o.h.t.d.s.BasicBinder - binding parameter [4] as [VARCHAR] - [new remark]
21:20:58.194 [main] TRACE o.h.t.d.s.BasicBinder - binding parameter [5] as [VARCHAR] - [152]

有没有办法解决这个问题，而无需为备注创建额外的实体？

我使用的是 Spring Boot 1.5.7 附带的休眠 5.0.12。数据库是postgresql 9.5.6。

Answer 1

我针对 5.0.12 和 5.2.10 对此进行了测试，在这两种情况下，为您的映射生成的表架构与您提供的不同。这可能是您最近升级过 Hibernate 的旧版应用程序吗？

例如，在 H2 上，我在测试中创建的表显示如下：

create table farm_detail_remark_AUD (
  REV integer not null, 
  field_detail_id integer not null, 
  remark varchar(255) not null, 
  field_id varchar(255) not null, 
  REVTYPE tinyint, 
  primary key (REV, field_detail_id, remark, field_id)
)

因此，对于您的方案，不会生成重复的主键，因为 remark 列包含在主键索引中，从而避免了您面临的问题。