Question

我在Spring Boot中使用Spring Data JPA。即使我使用了Lazy Fetch，Hibernate也会为实体中的所有关联生成SQL。我也使用了@OneToOne双向映射。两个方向都使用了LAZY fetch。当我从Parent-＆gt; Child访问数据时，它没有加载Child。但是Child-＆gt;父母急切地加载它。我查了一下，它为关联建立了sqls。真的很困惑。

父实体：员工：

@Entity
@Table(name = "employee")
public class Employee {
    @Id
    @Column(name = "employee_id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer employeeId;
    @Column(name = "employee_name")
    private String employeeName;
    @OneToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "company_id", referencedColumnName = "company_id")
    private Company company;
    //setters and getters
}

子实体：地址

@Entity
@Table(name = "address")
public class Address{
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "address_id")
    private Integer addressId;
    @Column(name = "address_name")
    private String addressName;
    @OneToOne(mappedBy = "address", fetch = FetchType.LAZY)
    @JsonIgnoreProperties(value = { "address"})
    private Employee employee;
    //getters and setters
}

我在两种情况下都使用了repository.findOne（id）。

对于Parent-＆gt; Child：我得到了结果和sqls如下： SQL：

Hibernate: select employee0_.employee_id as employee1_1_0_, employee0_.company_id as company_5_1_0_, employee0_.employee_desgn as employee2_1_0_, employee0_.employee_email as employee3_1_0_, employee0_.employee_name as employee4_1_0_ from employee employee0_ where employee0_.employee_id=?

输出：

[{＆＃34; EMPLOYEEID＆＃34：4，＆＃34; employeeName＆＃34;：＆＃34;格利扬＆＃34;＆＃34;地址＆＃34;：空，＆＃34;项目＆＃34;：空}]

来自Child-＆gt; Parent：我得到了结果和sqls如下： SQL：

Hibernate: select address0_.address_id as address_1_0_0_, address0_.address_name as address_2_0_0_ from address address0_ where address0_.address_id=?
Hibernate: select employee0_.employee_id as employee1_1_0_, employee0_.address_id as address_5_1_0_, employee0_.employee_desgn as employee2_1_0_, employee0_.employee_email as employee3_1_0_, employee0_.employee_name as employee4_1_0_ from employee employee0_ where employee0_.address_id=?

输出：

{＆＃34; addressId＆＃34;：2＆＃34; addressName＆＃34;：＆＃34; mykukun＆＃34;＆＃34;雇员＆＃34; {＆＃34; EMPLOYEEID＆＃34 ; 3＆＃34; employeeName＆＃34;：＆＃34; Krishna3＆＃34;}}

请告诉我，我需要做些什么让Lazy Fetch从Child到Parent工作？感谢

Spring Data JPA Lazy Fetch不适用于@OneToOne双向

父实体：员工：

子实体：地址

0 个答案: