小编Had*_*ter的帖子

我有一个学生实体.我的想法是在ArrayList中收集多个学生对象,并将该列表中的所有对象保存到数据库中.什么时候使用@ElementCollection注释？它适用于这种情况吗？

学生:

package basic;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class Student {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;
    private String name;

    public Student() {

    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "Student [id=" + id + ", name=" + name + …

我正在尝试使用 Hibernate 处理 OneToMany 关系。我正在使用 @Temporal 注释来告诉 hibernate 有关数据字段的信息。我不知道为什么我会在这里收到此错误。看起来日期格式有问题。请让我知道如何解决它。

顾客

package regular;

import java.util.List;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToMany;

@Entity
public class Customers {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int customer_id;
    private String customerName;
    private String contactName;
    private String address;
    private String city;
    private String postalCode;
    private String country;

    @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, orphanRemoval = true)
    @JoinColumn(name = "customer_id")
    private List<Orders> order;

    public Customers() {
    }

    public …