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我花了几天时间解决一个奇怪的问题。StackOverflow 中有很多类似的帖子，我已经检查了很多，但我找不到与此类似的内容。我有一个Human家长班

import javax.persistence.*;
import java.util.Date;

@Entity(name = "Human")
@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
public abstract class Human
{
    @Id
    @Column(name = "human_id", nullable = false)
    @GeneratedValue(strategy = GenerationType.SEQUENCE)
    private Long id;

    @JsonProperty("name")
    private String name;

    @JsonProperty("date_of_birth")
    private Date dateOfBirth;

    @Embedded
    @JsonProperty("authentication_credential")
    private AuthenticationCredentials authCred;

    // constructors + setter/getters
}

一个User子类：

import javax.persistence.*;
import java.util.Date;

@Entity(name = "User")
@Table(name = "end_user")
public class User extends Human
{
    @OneToOne(mappedBy = "user",
              cascade = CascadeType.ALL,
              fetch = FetchType.LAZY,
              optional = false)
    @JsonProperty("contact_numbers")
    private CollectionOfContactMethods contactNumbers;

    @JsonProperty("telephone")
    private String telephone;

    // constructors + setter/getters
 }

并且还CollectionOfContactMethods与 的构成关系User。

import javax.persistence.*;
import java.util.List;

@Entity(name = "CollectionOfContactMethods")
@Table(name = "collection_of_contact_methods")
public class CollectionOfContactMethods
{
    @Id
    @Column(name = "collection_id", nullable = false)
    @GeneratedValue(strategy = GenerationType.SEQUENCE)
    private Long id;

    @OneToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "ext_human_id", referencedColumnName = "human_id")
    private User user;

    @JsonProperty("email")
    private String email;

    // constructors + setter/getters
}

根据 ER 图，计划是这样的：

在此处输入图像描述

但是，我在数据库级别得到的是：

在此处输入图像描述

我很感激你花费的时间。谢谢。

PS：这里是UserController

@RestController
@RequestMapping("api/v1/user/")
public class UserController
{
    @Autowired
    UserService userService;

    @GetMapping(value = "users")
    Iterable<User> list()
    {
        Iterable<User> retVal = userService.findAll();
        return retVal;
    }

    @RequestMapping(value = "user", method = RequestMethod.POST)
    User create(@RequestBody User user)
    {
        return userService.save(user);
    }

    @RequestMapping(value = "user/{id}",  method = RequestMethod.GET )
    Optional<User> get(@PathVariable Long id)
    {
        return userService.findById(id);
    }
}

还有UserService：

import com.tsakirogf.schedu.model.human.User;
import org.springframework.data.repository.CrudRepository;

public interface UserService extends CrudRepository<User, Long>
{
}
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1 回答 1

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User由于您在和之间具有双向关系CollectionOfContactMethods，因此问题可能是CollectionOfContactMethods user您尝试创建它时为空，因此数据库中的数据为空或not-null property references a null or transient value : com.tsakirogf.schedu.model.CollectionOfContactMethods.user错误。尝试以下操作：

@RequestMapping(value = "user", method = RequestMethod.POST)
User create(@RequestBody User user) {
    CollectionOfContactMethods contactNumbers = user.getContactNumbers();
    contactNumbers.setUser(user);
    user.setContactNumbers(contactNumbers);
    return userService.save(user);
}
于 2021-10-01T16:40:50.797 回答