使用JPA的一对一关系
我使用JPA创建了两个表。我需要给出这些表之间的1-1关系。谁能告诉我如何给出这些表之间的关系。只需在表中添加一列,用FK约束“拥有”关系即可。例如: CREATE TABLE MYENTITYA ( ID BIGINT NOT NULL, MYENTITYB_ID BIGINT ); CREATE TABLE MYENTITYB ( ID BIGINT NOT NULL ); ALTER TABLE MYENTITYA ADD CONSTRAINT SQL100326144838300 PRIMARY KEY (ID); ALTER TABLE MYENTITYB ADD CONSTRAINT SQL100326144838430 PRIMARY KEY (ID); ALTER TABLE MYENTITYA ADD CONSTRAINT FKB65AC952578E2EA3 FOREIGN KEY (MYENTITYB_ID) REFERENCES MYENTITYB (ID); 如果使用JPA的一对一关系,jpa,entity,entity-relationship,Jpa,Entity,Entity Relationship,我使用JPA创建了两个表。我需要给出这些表之间的1-1关系。谁能告诉我如何给出这些表之间的关系。只需在表中添加一列,用FK约束“拥有”关系即可。例如: CREATE TABLE MYENTITYA ( ID BIGINT NOT NULL, MYENTITYB_ID BIGINT ); CREATE TABLE MYENTITYB ( ID BIGINT NOT NULL ); ALTER TABLE MYENTITYA ADD
EntityA
和EntityB
之间的关系不是可选的,则添加notnull
约束
@Entity
public class MyEntityA implements Serializable {
private Long id;
private MyEntityB myEntityB;
@Id
@GeneratedValue
public Long getId() {
return this.id;
}
@OneToOne(optional = true, cascade = CascadeType.ALL)
public MyEntityB getEntityB() {
return this.myEntityB;
}
//...
}
@Entity
public class MyEntityB implements Serializable {
private Long id;
@Id
@GeneratedValue
public Long getId() {
return id;
}
//...
}