Question

我一直在尝试了解Hibernate映射，但我只是不明白。在春季项目中使用休眠模式。 db的mysql工作台。

每个表都有一个ID，优惠券和公司。当公司创建优惠券时，我希望优惠券ID和公司ID转到名为companyCoupon的第三张表，并在该表中进行映射，这样：

一家公司可能有许多优惠券。优惠券可能与一家公司关联。

公司ID = 1；优惠券ID = 1;

companycoupon- compid = 1; coupid = 1;

ive创建了第三个表，并伪造了映射到其他表的键。

有人吗？有任何想法吗？好文章要阅读？

编辑：

zipCodePattern =  /^\d{4} ?[a-z]{2}$/i;

2：

package com.example.CouponProjectCore.entity;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToOne;
import javax.persistence.Table;

@Entity
@Table(name = "coupons")
public class Coupon {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name="coupid")
    private long coupid;
    @Column(name="title")
    private String title;
    @Column(name="startd")
    private String startd;
    @Column(name="endd")
    private String endd;    
    @Column(name="amount")
    private int amount; 
    @Column(name="type")
    private String type;
    @Column(name="message")
    private String message; 
    @Column(name="price")
    private double price;
    @Column(name="image")
    private String image;

    @ManyToOne()
    private Company company;


    public Coupon(String title, String startd, String endd, int amount, String type, String message, double price,
            String image) {
        super();
        this.title = title;
        this.startd = startd;
        this.endd = endd;
        this.amount = amount;
        this.type = type;
        this.message = message;
        this.price = price;
        this.image = image;

    }





    public Company getCompany() {
        return company;
    }





    public void setCompany(Company company) {
        this.company = company;
    }





    public long getCoupid() {
        return coupid;
    }

    public void setCoupid(long coupid) {
        this.coupid = coupid;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getStartd() {
        return startd;
    }

    public void setStartd(String startd) {
        this.startd = startd;
    }

    public String getEndd() {
        return endd;
    }

    public void setEndd(String endd) {
        this.endd = endd;
    }

    public int getAmount() {
        return amount;
    }

    public void setAmount(int amount) {
        this.amount = amount;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public String getImage() {
        return image;
    }

    public void setImage(String image) {
        this.image = image;
    }


    @Override
    public String toString() {
        return "Coupon [coupid=" + coupid + ", title=" + title + ", startd=" + startd + ", endd=" + endd + ", amount="
                + amount + ", type=" + type + ", message=" + message + ", price=" + price + ", image=" + image
             + "]";
    }
}

Answer 1

好的，那么您无需添加第三张表，只需添加带有companyId的优惠券列表

//add in Company Enitity
@OneToMany(cascade=CascadeType.ALL)
    @JoinColumn(name="COMPANY_ID")
    private List<CouponsEntity> coupons;

//add in Coupons Enitity
 @ManyToOne
    private CompanyEntity company;

这是可以理解的静态示例

Company user=  new Company();

user.setId(1);
user.setComp_name("qwqwq");
user.setEmail("dde@gmail.com");
user.setPassword("w1w");

Coupon c= new Coupon("wssw", "2019", "2201", 1, "1w1", "1w1w", 2.3, "w1w1w1", user);
Coupon c1= new Coupon("wssw", "2019", "2201", 1, "1w1", "1w1w", 2.3, "w1w1w1", user);
Coupon c2= new Coupon("wssw", "2019", "2201", 1, "1w1", "1w1w", 2.3, "w1w1w1", user);
Coupon c3= new Coupon("wssw", "2019", "2201", 1, "1w1", "1w1w", 2.3, "w1w1w1", user);

List<Coupon> coupons = new ArrayList<Coupon>();

coupons.add(c);
coupons.add(c1);
coupons.add(c2);
coupons.add(c3);


user.setCoupons(coupons);

使用其ID从两个表中创建一个表

1 个答案: