@SecondaryTables：映射一個實體到多張表

Question

我很清楚地知道@SecondaryTable註釋是單個實體的字段映射到多張表，就好像這些表合併爲一單身。
我在實現這個概念時遇到問題。 有3類需要被持續下去，

的Class1其2個字段出4要被存儲在2個其他不同的表

@Entity 
@Table(name = "MAIN_CAT") 
@SecondaryTables({ 

    @SecondaryTable(name = "CAT_1", pkJoinColumns = { 
      @PrimaryKeyJoinColumn(name = "CAT1_PK", referencedColumnName = "id") 
     }), 
    @SecondaryTable(name = "CAT_2", uniqueConstraints = { 
      @UniqueConstraint(columnNames = {"storyPart2"}) 
    }) 
}) 
public class Cat { 

    @Id@GeneratedValue 
    private Long id; 

    private String catName; 

    @Column(table = "CAT_1") 
    private String storyPart1; // this field is going to be stored in CAT_1 

    @Column(table = "CAT_2") 
    private String storyPart2; // and so on 
    // getters and setters 
} 

2類：此類當持續存儲時，將storyPart1字段存儲在上述持久類中

@Entity 
@Table(name = "CAT_1") 
public class CatOne { 

    @Id 
    @GeneratedValue 
    @Column(name = "CAT1_PK") 
    private Long CAT1_PK; 

    @Column(name = "CATNAME_1") 
    private String catName1; 

    @Column(name = "CATAGE_1") 
    private String catAge1; 
    // getters and setters 
} 

3類：當持續將存儲持久類storyPart2字段1

@Entity 
@Table(name = "CAT_2") 
public class CatTwo { 

    @Id 
    @GeneratedValue 
    private Long id; 

    @Column(name = "CATNAME_2") 
    private String catName2; 

    @Column(name = "CATAGE_2") 
    private String catAge2; 
    // getters and setters 
} 

在數據庫中創建的3個表是這個類：

對於第1類：

CREATE TABLE main_cat 
(
    id bigint NOT NULL, 
    catname character varying(255), 
    CONSTRAINT main_cat_pkey PRIMARY KEY (id) 
) 

對於2類：

CREATE TABLE cat_1 
(
    storypart1 character varying(255), 
    cat1_pk bigint NOT NULL, 
    catage_1 character varying(255), 
    catname_1 character varying(255), 
    CONSTRAINT cat_1_pkey PRIMARY KEY (cat1_pk), 
    CONSTRAINT fk_kvtvo6nrv78wxkm0kv01k9kdq FOREIGN KEY (cat1_pk) 
     REFERENCES main_cat (id) MATCH SIMPLE 
     ON UPDATE NO ACTION ON DELETE NO ACTION 
) 

對於第3類：

CREATE TABLE cat_2 
(
    storypart2 character varying(255), 
    id bigint NOT NULL, 
    catage_2 character varying(255), 
    catname_2 character varying(255), 
    CONSTRAINT cat_2_pkey PRIMARY KEY (id), 
    CONSTRAINT fk_2duj6ebg3504x18mlw2xkpvg6 FOREIGN KEY (id) 
     REFERENCES main_cat (id) MATCH SIMPLE 
     ON UPDATE NO ACTION ON DELETE NO ACTION, 
    CONSTRAINT uk_5ko8732qslvvx98gy0q666qrf UNIQUE (storypart2) 
) 

的問題是，而不是插入在CAT_1一個記錄，它觸發2個插入用於相同。在CAT_2中插入記錄會發生同樣的情況。

  Cat cat = new Cat(); 

     cat.setCatName("CAT Name"); 
     cat.setStoryPart1("STORYPART1"); 
     cat.setStoryPart2("STORYPART2"); 

     CatOne catOne = new CatOne(); 

     catOne.setCatAge1("10"); 
     catOne.setCatName1("catName1"); 

     CatTwo catTwo = new CatTwo(); 

     catTwo.setCatAge2("12"); 
     catTwo.setCatName2("catName2"); 

     session.save(cat); 
     session.save(catOne); 
     session.save(catTwo); 

聲明：

Hibernate: insert into CAT_1 (storyPart1, CAT1_PK) values (?, ?) 
Hibernate: insert into CAT_1 (CATAGE_1, CATNAME_1, CAT1_PK) values (?, ?, ?) 

由於單個插入語句的分裂成2語句時，Hibernate拋出此錯誤。

Caused by: org.postgresql.util.PSQLException: ERROR: insert or update 
on table "cat_1" violates foreign key constraint 
"fk_kvtvo6nrv78wxkm0kv01k9kdq" Detail: Key (cat1_pk)=(2) is not 
present in table "main_cat". 

看起來像我已經以錯誤的方式實現了@SecondaryTable概念。如何讓Hibernate在這種情況下觸發單個插入呢？

Answer 1

如果您已經使用某個表作爲實體的輔助表，那麼將該表映射到另一個實體也不是一個好主意。次表應該被理解爲指定實體的另一個表格，只有通過該實體才能管理。

如果您已經有二手錶的實體，那麼使用普通實體映射@OneToOne，@ManyToOne等