[英]JPA unidirectional one-to-many relationship persist
我试图保持3个具有一对多关系的实体,但我做对了。 这就是我所拥有的:
@Entity
@Table(name = "tb_person")
public class Person {
@Id
@SequenceGenerator(name = "my_seq", sequenceName = "pk_seq", allocationSize = 1)
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "my_seq")
@Column(name="person_id")
private long personId;
@OneToMany(cascade = {CascadeType.PERSIST, CascadeType.MERGE})
@JoinColumn(name = "person_id", referencedColumnName = "person_id")
private List<Phone> phones;
}
@Entity
@IdClass(PersonBrandId.class)
@Table(name = "tb_person_phone")
public class Phone {
@Id
@Column(name = "retailer_id")
private long personId;
@Id
@Column(name = "brand_code")
private String brandCode;
@OneToMany(cascade = {CascadeType.PERSIST, CascadeType.MERGE})
@JoinColumns({
@JoinColumn(name = "brand_code", referencedColumnName = "brand_code", insertable = false, updatable = false),
@JoinColumn(name = "person_id", referencedColumnName = "person_id", insertable = false, updatable = false)})
List<Mobile> mobiles;
...other fields...
}
@Entity
@Table(name = "tb_mobile")
public class Mobile {
@Id
@SequenceGenerator(name = "my_seq2", sequenceName = "pk_seq2", allocationSize = 1)
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "my_seq2")
@Column(name="mobile_id")
private long mobileId;
@Column(name = "person_id")
private long personId;
...other fields...
}
因此,我要达到的目的是仅保留Person,并且由于级联,Phone和Mobile将自动保留。 例:
Person person = new Person();
Phone phone = new Phone();
Mobile mobile = new Mobile();
phone.getMobiles().add(mobile);
person.getPhones().add(phone);
em.persist(person);
问题是我收到一条错误消息,说tb_person_phone.person_id不能为null。
该关系是单向的,因此我没有添加ManyToOne端。
为了回答一些评论:
关系如下:
一个人可以有多个电话。
电话具有复合主键:
- person_id in Person - brand_code in Brand (a table with a list of brands)
移动设备具有主键:mobile_id
has two FK: - person_id and brand_code both referencing the table Phone
SQL生成表:
CREATE TABLE "TB_PERSON"
( "PERSON_ID" NUMBER NOT NULL ENABLE,
"PERSON_NAME" VARCHAR2(100 BYTE) NOT NULL ENABLE,
CONSTRAINT "PERSON_PK" PRIMARY KEY ("PERSON_ID")
);
CREATE TABLE "TB_PERSON_PHONE"
( "PERSON_ID" NUMBER NOT NULL ENABLE,
"BRAND_CODE" VARCHAR2(30 BYTE) NOT NULL ENABLE,
"ATTR1" VARCHAR2(1 BYTE),
"ATTR2" VARCHAR2(100 BYTE),
CONSTRAINT "PERSON_PHONE_PK" PRIMARY KEY ("PERSON_ID", "BRAND_CODE")
FOREIGN KEY ("PERSON_ID")
REFERENCES "TB_PERSON" ("PERSON_ID") ENABLE,
FOREIGN KEY ("BRAND_CODE")
REFERENCES "TB_BRAND" ("BRAND_CODE") ENABLE
);
CREATE TABLE "TB_MOBILE"
( "MOBILE_ID" NUMBER NOT NULL ENABLE,
"PERSON_ID" NUMBER NOT NULL ENABLE,
"BRAND_CODE" VARCHAR2(30 BYTE) NOT NULL ENABLE,
"NUMBER" VARCHAR2(30 BYTE) NOT NULL ENABLE,
"ATTR1" VARCHAR2(100 BYTE),
"ATTR2" VARCHAR2(100 BYTE),
CONSTRAINT "MOBILE_PK" PRIMARY KEY ("MOBILE_ID"),
CONSTRAINT "MOBILE_UQ" UNIQUE ("NUMBER", "PERSON_ID", "BRAND_CODE")
USING INDEX (CREATE UNIQUE INDEX "MOBILE_UQ_IDX" ON "TB_MOBILE" ("NUMBER", "PERSON_ID", "BRAND_CODE"),
FOREIGN KEY ("PERSON_ID", "BRAND_CODE")
REFERENCES "TB_PERSON_PHONE" ("PERSON_ID", "BRAND_CODE") ENABLE
);
为移动和电话实体的主键设置@GeneratedValue(strategy = GenerationType.AUTO)
。
您正在使用人员ID作为Phone类中的标识符
@Id
@Column(name = "retailer_id")
private long personId;
放置另一列作为ID并添加一些生成ID策略或
Person person = new Person();
em.persist(person); //<
Phone phone = new Phone();
Mobile mobile = new Mobile();
phone.getMobiles().add(mobile);
person.getPhones().add(phone);
phone.setPersonId(person.getId()); // <
em.persist(person);
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