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我有2个实体Customer和Address,关系是一个地址可以属于多个客户。JPA:问题持续存在一个OneToMany关系的2个实体
以下是客户类,您可以看到它具有对地址对象的引用,在底层客户表中它是地址的标识。我省略了getter和setter以及一些简单的变量。
@Entity
@Table(name = "customer")
public class Customer implements Serializable {
@Id
@GeneratedValue
@Column(name = "customer_id")
private int customerId;
@ManyToOne
@JoinColumn(name = "store_id")
private Store store;
@ManyToOne
@JoinColumn(name = "address_id")
private Address address;
........
}
以下是地址类。
//Address Class
@Entity
@Table(name = "address")
public class Address implements Serializable {
@Id
@GeneratedValue
@Column(name = "address_id")
private int addressId;
@JoinColumn(name = "city_id")
@ManyToOne
private City city;
@OneToMany(cascade = CascadeType.ALL, mappedBy = "address")
@JsonIgnore
List<Customer> customers;
......
}
我试图在一次调用中坚持一个新客户和一个新地址,像下面一样保持。我省略了一些我设定的变量。
Customer cus = new Customer();
Address addr= new Address();
........
cus.setAddress(addr)
List<Customer> cusList= new ArrayList<>();
cusList.add(cus);
addr.setCustomers(cusList);
entityManager.persist(cus)
但我得到一个错误,说客户表中的address_id为空。我原以为JPA会插入新的地址,然后插入新的地址标识列设置为新的地址标识的客户?我的思想错了吗?或者我在映射中犯了一个错误,或者我如何坚持这些实体?
另一种方法,我可以做到这一点是先坚持住地址,然后坚持客户,但宁愿如果可能的话在一个坚持做。
下面是基础表。
//Customer Table
CREATE TABLE `customer` (
`customer_id` smallint(5) unsigned NOT NULL AUTO_INCREMENT,
`store_id` tinyint(3) unsigned NOT NULL,
`first_name` varchar(45) NOT NULL,
`last_name` varchar(45) NOT NULL,
`email` varchar(50) DEFAULT NULL,
`address_id` smallint(5) unsigned NOT NULL,
`active` tinyint(1) NOT NULL DEFAULT '1',
`create_date` datetime NOT NULL,
`last_update` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`customer_id`),
KEY `idx_fk_store_id` (`store_id`),
KEY `idx_fk_address_id` (`address_id`),
KEY `idx_last_name` (`last_name`),
CONSTRAINT `fk_customer_address` FOREIGN KEY (`address_id`) REFERENCES `address` (`address_id`) ON UPDATE CASCADE,
CONSTRAINT `fk_customer_store` FOREIGN KEY (`store_id`) REFERENCES `store` (`store_id`) ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=608 DEFAULT CHARSET=utf8;
/Address Table
CREATE TABLE `address` (
`address_id` smallint(5) unsigned NOT NULL AUTO_INCREMENT,
`address` varchar(50) NOT NULL,
`address2` varchar(50) DEFAULT NULL,
`district` varchar(20) NOT NULL,
`city_id` smallint(5) unsigned NOT NULL,
`postal_code` varchar(10) DEFAULT NULL,
`phone` varchar(20) NOT NULL,
`last_update` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`address_id`),
KEY `idx_fk_city_id` (`city_id`),
CONSTRAINT `fk_address_city` FOREIGN KEY (`city_id`) REFERENCES `city` (`city_id`) ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=619 DEFAULT CHARSET=utf8;
谢谢。
谢谢你的工作。 – JCS
@JCS不客气 –