Question

我正在使用集成在 MySQL Workbench 中的数据库“world”

我尝试过提交事务，但出现了很长的错误

怎么了？

import javax.persistence.*;

public class MyPC{
    public static void main(String[] args) {
        EntityManagerFactory emf = Persistence.createEntityManagerFactory("test_persistence");
        EntityManager em = emf.createEntityManager();

        System.out.println("Start hibernate test");
        em.getTransaction().begin();
        city Mon = new city(15000, "FFF", "BBB", "xktyjdj", 35000);
        em.persist(Mon);
        em.getTransaction().commit();
        System.out.println("New ID is "+Mon.getID());
    }
}

city.java

import javax.persistence.Entity;

import javax.persistence.*;

@Entity
@Table(name = "city")
public class city{
    @Id
    @Column(name = "ID")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int ID;
    @Column(name = "Name")
    private String Name;
    @Column(name = "CountryCode")
    private String CountryCode;
    @Column(name = "District")
    private String District;
    @Column(name = "Population")
    private int Population;

    public city(int id, String name, String countrycode, String district, int population){
        ID = id;
        Name = name;
        CountryCode = countrycode;
        District = district;
        Population = population;
    }

    public int getID(){
        return ID;
    }
    public String getname(){
        return Name;
    }

}

这个错误

线程“main”中的异常javax.persistence.PersistenceException：org.hibernate.PersistentObjectException：分离的实体传递给persist：city 在 org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:154) 在 org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:181) 在 org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:188) 在 org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:726) 在 org.hibernate.internal.SessionImpl.persist(SessionImpl.java:706) 在 MyPC.main(MyPC.java:11) 引起：org.hibernate.PersistentObjectException：分离的实体传递给持久化：城市在 org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:120) 在 org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:55) 在 org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:93) 在 org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:720) ... 2个

javax.persistence.PersistenceException: org.hibernate.PersistentObjectException: 分离实体传递给持久数据库“world”

0 个答案: