java - 无法使用 Spring Boot 将 ArrayList 中超过 2 个元素保存到 MySQL？

Question

我无法使用 SpringBoot 将 ArrayList 中超过 2 个元素保存到 MySQL。当我使用数组中的一个对象发出发布请求(Postman 或使用 Alamofire)时，我会得到状态代码 200，否则我会在 springboot 控制台中得到状态代码 500 和此错误消息:

java.sql.SQLIntegrityConstraintViolationException: Cannot add or update a child row: a foreign key constraint fails (quran-pro-core.surah, CONSTRAINT FKibuxjpjiwpq46220g7sn7y1q FOREIGN KEY (id) REFERENCES reciter (documentid))

这些是我的类(class):

@RestController
public class ReciterController {

     @Autowired
     private ReciterService reciterService;

     @PostMapping("/reciters")
     public String saveReciter(@RequestBody Reciter reciter) {
     reciterService.saveReciter(reciter);
     return "SUCCESS";
   }
}

@Service
public class ReciterService {

     @Autowired
     private ReciterRepostitory reciterRepository;

     public void saveReciter(Reciter reciter) {
     reciterRepository.save(reciter);
     }
}

@Entity
public class Reciter {

     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long documentID;

     @Column
     private String name;
     @Column
     private String image;
     @OneToMany(mappedBy="id", cascade = CascadeType.ALL)
     private List<Surah> surahs;

     // Constructor and getters and setters
}

@Entity
public class Surah {

     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;

     @Column
     private String name;
     @Column
     private int number;

     // Constructor and getters and setters

}

这个机构的工作原理:

{
"name": "reciter1",
"image": "/reciter1/image.png",
"surahs": [
         {
            "name": "LOLll",
            "number": 0
        }

]
}

这不是:

{
"name": "reciter1",
"image": "/reciter1/image.png",
"surahs": [
         {
            "name": "LOLll",
            "number": 0
        },
        {
            "name": "test2",
            "number": 1
        }
]
}

enter code here

Answer 1

您的ManyToOne配置不正确，mappedBy元素必须用于指定作为关系所有者的实体的关系字段或属性

1. 第一个建议，使用双向关系:

public class Reciter {

     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long documentID;

     @Column
     private String name;
     @Column
     private String image;
     @OneToMany(mappedBy="reciter", cascade = CascadeType.ALL)
     private List<Surah> surahs;

     // Constructor and getters and setters

}

@Entity
public class Surah {

     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;

     @Column
     private String name;
     @Column
     private int number;

     @ManyToOne
    private Reciter reciter;
}

或使用单向关系:

 @OneToMany(cascade = CascadeType.ALL)
 private List<Surah> surahs;