java - 数据库持久化过程中的hibernate嵌套异常

Question

我在插入记录数据库期间遇到以下问题。

2018-08-12 16:06:26.874 WARN 5482 --- [nio-8080-exec-2] o.h.engine.jdbc.spi.SqlExceptionHelper : SQL Error: 1364, SQLState: HY000 2018-08-12 16:06:26.875 ERROR 5482 --- [nio-8080-exec-2] o.h.engine.jdbc.spi.SqlExceptionHelper : Field 'country_id' doesn't have a default value Query is: insert into bi_person (additional_info, gender_id, last_name, name) values (?, ?, ?, ?), parameters ['Java master',48,'WW','John'] 2018-08-12 16:06:27.047 ERROR 5482 --- [nio-8080-exec-2] o.a.c.c.C.[.[.[.[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [/bi-message-svc/v1] threw exception [Request processing failed; nested exception is org.springframework.orm.jpa.JpaSystemException: could not execute statement; nested exception is org.hibernate.exception.GenericJDBCException: could not execute statement] with root cause

org.mariadb.jdbc.internal.util.dao.QueryException: Field 'country_id' doesn't have a default value Query is: insert into bi_person (additional_info, gender_id, last_name, name) values (?, ?, ?, ?), parameters ['Java master',48,'WW','John']*

//国家:

@Table(name = "bi_country")
@Entity
public class Country {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id_country")
    private Integer id;

    @Column(name = "name")
    private String name;

    @ManyToMany(cascade = CascadeType.ALL)
    @JoinTable(name="country_book", joinColumns=@JoinColumn(name="id_country"), inverseJoinColumns=@JoinColumn(name="id_person"))
    private Set<Person> persons;

//性别:

@Table(name = "bi_gender")
@Entity
public class Gender {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id_gender")
    private Integer id;

    @Column(name = "name")
    private String name;

//人

@Table(name = "bi_person")
@Entity
public class Person {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id_person")
    private Integer id;

    @Column(name = "name")
    private String name;
    @Column(name = "last_name")
    private String lastName;
    @Column(name = "additional_info")
    private String additionalInfo;


    @ManyToOne
    private Gender gender;

    @ManyToMany(cascade=CascadeType.ALL)
    private Set<Country> countries;

Answer 1

您只需仔细阅读错误消息即可。它说:

Field 'country_id' doesn't have a default value Query is: insert into bi_person (additional_info, gender_id, last_name, name) ...

因此，您的 bi_person 表有一个名为 country_id 的字段，该字段没有任何默认值。当然，Hibernate 不会在该字段中插入任​​何内容，因为它在实体 Person 中没有任何此类字段。所以你会得到这个异常(exception)。

数据库架构与您的实体设计不匹配。修复其中一个或另一个或两者，并确保它们彼此兼容。

如果您的数据库设计，一个人有一个国家/地区(因此列country_id为person)。在你的对象设计中，一个人有许多国家。