java - 键 'PRIMARY' 的重复实体

Question

我的问题是，当我使级联持续存在时，它会抛出异常( MySQLIntegrityConstraintViolationException )。 我正在使用Spring Data;用于保存我的数据。

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'Bloomberg' for key 'PRIMARY'

新闻类:

@Entity
public class News implements Serializable {

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

    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "company_name")
    private Company company;

    ...
}

公司类别:

@Entity
@Table(name = "company")
public class Company implements Serializable{

    @Id
    @Column(unique = true,nullable = false)
    private String name;

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "company",fetch = FetchType.EAGER)
    private List<News> newsList;

   ...
}

我正在使用此代码来持久化:

public void parseDB() throws IOException {
    List<News> newsList = new ArrayList<>();

    Map<String, Company> companyMap = ((List<Company>) companyRepository.findAll()).stream().collect(Collectors.toMap(Company::getName, company -> company));

    newsList.addAll(WebPagesParser.parseCategory("...", "...", companyMap));
    newsList.forEach(newsService::create);
    }


public static List<News> parseCategory(String url, String category,Map<String,Company> companyMap) throws IOException {
       ... 
      Company company; 
      if (companyMap.containsKey(name)) {
                    company = companyMap.get(name);
                } else {
                    company = new Company();
                    company.setName(top.get(1).text());
                }
       news.setCompany(company);
      ...
      }

它给了我新的异常(exception)

org.springframework.dao.InvalidDataAccessApiUsageException: detached entity passed to persist: com.example.inosmi.database.data.News; nested exception is org.hibernate.PersistentObjectException: detached entity passed to persist: com.example.inosmi.database.data.News

完成: 已经解决了一半的问题，我仍然不知道它在哪里，但它有效。谢谢大家!

Answer 1

MySQL 告诉您正在尝试插入具有相同主键的多行

与此相关的代码在这里

@Id
@Column(unique = true, nullable = false)
private String name;

您正在加载的数据有多行带有公司名称 Bloomberg