Hibernate一对多和多对多

一对多

一对多单向

@Entity
@Table(name = "cz_user")
public class Users {@Column(name = "user_id")@Id@GeneratedValue(strategy = GenerationType.AUTO)private Integer userId;@Column(name = "user_name")private String username;@Column(name = "email")private String email;@Column(name = "password")private String password;@Column(name = "reg_time")private Date regTime;@OneToMany(cascade = CascadeType.ALL,orphanRemoval = true)@JoinColumn(name = "user_id")//外键维护private List<Address> addressList = new ArrayList<Address>();public Users() {}//这里属性的get方法需要有,set方法不需要，当然你可以加上

@Entity
@Table(name = "cz_address")
public class Address {@Column(name = "address_id")@Id@GeneratedValue(strategy = GenerationType.AUTO)private Integer addressId;@Column(name = "consignee")private String consignee;@Column(name = "province")private Integer province;@Column(name = "city")private Integer city;@Column(name = "district")private Integer district;@Column(name = "street")private String street;@Column(name = "zipcode")private String zipcode;@Column(name = "telphone")private String telphone;@Column(name = "mobile")private String mobile;public Address() {}//这里属性的get方法需要有,set方法不需要，当然你可以加上

/**测试级联保存*/
@Transactional
@Overridepublic void test() {List<Address> addresses = new ArrayList<Address>();Address consignee1 = new Address("consignee12", 12, 12, 12);Address consignee2 = new Address("consignee22", 22, 22, 22);Address consignee3 = new Address("consignee32", 32, 32, 32);Address consignee4 = new Address("consignee42", 42, 42, 42);addresses.add(consignee1);addresses.add(consignee2);addresses.add(consignee3);addresses.add(consignee4);Users users1 = new Users(null, "username2", "email2", "password2", new Date(), addresses);userAddressDao.saveUser(users1);if (addresses != null && addresses.size() > 0){for (Address address : addresses) {userAddressDao.updateAddress(address,users1.getUserId());}}}

public void saveUser(Users users) {getCurrentSession().save(users);}
@Overridepublic void updateAddress(Address address,int user_id) {int o = getCurrentSession().createQuery("update "+Address.class.getName()+" set user_id = :user_id where addressId = :addressId").setParameter("user_id",user_id).setParameter("addressId",address.getAddressId()).executeUpdate();logger.warn("外键成功:" + o);}

这种单向一对多的级联保存，只需要保存"一方"，保存成功之后，“一方”，"多方"的主键会自动回填，然后再去更新外键。这种单向的一对多情况下，"多方"基本上我们是使用不到的。

一对多双向

@Entity
@Table(name = "cz_user")
public class Users {@Column(name = "user_id")@Id@GeneratedValue(strategy = GenerationType.AUTO)private Integer userId;@Column(name = "user_name")private String username;@Column(name = "email")private String email;@Column(name = "password")private String password;@Column(name = "reg_time")private Date regTime;@OneToMany(cascade = CascadeType.ALL,orphanRemoval = true,mappedBy = "users")private List<Address> addressList = new ArrayList<Address>();public Users() {}//这里属性的get方法需要有,set方法不需要，当然你可以加上

@Entity
@Table(name = "cz_address")
public class Address {@Column(name = "address_id")@Id@GeneratedValue(strategy = GenerationType.AUTO)private Integer addressId;@Column(name = "consignee")private String consignee;@Column(name = "province")private Integer province;@Column(name = "city")private Integer city;@Column(name = "district")private Integer district;@Column(name = "street")private String street;@Column(name = "zipcode")private String zipcode;@Column(name = "telphone")private String telphone;@Column(name = "mobile")private String mobile;@ManyToOne(fetch = FetchType.LAZY)@JoinColumn(name = "user_id")//外键private Users users;//这里属性的get方法需要有,set方法不需要，当然你可以加上

@Transactional@Overridepublic void test() {List<Address> addresses = new ArrayList<Address>();Address consignee1 = new Address("consignee12", 12, 12, 12);Address consignee2 = new Address("consignee22", 22, 22, 22);Address consignee3 = new Address("consignee32", 32, 32, 32);Address consignee4 = new Address("consignee42", 42, 42, 42);addresses.add(consignee1);addresses.add(consignee2);addresses.add(consignee3);addresses.add(consignee4);Users users1 = new Users(null, "username2", "email2", "password2", new Date(), addresses);userAddressDao.saveUser(users1);if (addresses != null && addresses.size() > 0){for (Address address : addresses) {userAddressDao.updateAddress(address,users1.getUserId());}}}

  @Overridepublic void saveUser(Users users) {getCurrentSession().save(users);}@Overridepublic void updateAddress(Address address,int user_id) {int o = getCurrentSession().createQuery("update "+Address.class.getName()+" set user_id = :user_id where addressId = :addressId").setParameter("user_id",user_id).setParameter("addressId",address.getAddressId()).executeUpdate();logger.warn("外键成功:" + o);}

这种单向一对多的级联保存，只需要保存"一方"，保存成功之后，“一方”，"多方"的主键会自动回填，然后再去更新外键。这种双向的一对多情况下，是使用最多的
上面两种情况的执行结果

Hibernate: insert intocz_user(email, password, reg_time, user_name) values(?, ?, ?, ?)
Hibernate: insert intocz_address(city, consignee, district, mobile, province, street, telphone, user_id, zipcode) values(?, ?, ?, ?, ?, ?, ?, ?, ?)
Hibernate: insert intocz_address(city, consignee, district, mobile, province, street, telphone, user_id, zipcode) values(?, ?, ?, ?, ?, ?, ?, ?, ?)
Hibernate: insert intocz_address(city, consignee, district, mobile, province, street, telphone, user_id, zipcode) values(?, ?, ?, ?, ?, ?, ?, ?, ?)
Hibernate: insert intocz_address(city, consignee, district, mobile, province, street, telphone, user_id, zipcode) values(?, ?, ?, ?, ?, ?, ?, ?, ?)
Hibernate: updatecz_address setuser_id=? whereaddress_id=?
2021-11-16 15:07:33,193 WARN [com.xysd.ssh.repository.UserAddressDaoImpl] - 外键成功:1
Hibernate: updatecz_address setuser_id=? whereaddress_id=?
2021-11-16 15:07:33,221 WARN [com.xysd.ssh.repository.UserAddressDaoImpl] - 外键成功:1
Hibernate: updatecz_address setuser_id=? whereaddress_id=?
2021-11-16 15:07:33,251 WARN [com.xysd.ssh.repository.UserAddressDaoImpl] - 外键成功:1
Hibernate: updatecz_address setuser_id=? whereaddress_id=?
2021-11-16 15:07:33,309 WARN [com.xysd.ssh.repository.UserAddressDaoImpl] - 外键成功:1

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Hibernate一对多和多对多

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