领导者使用Spring

Question

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请始终分享您的努力 /代码以及您的问题。

对我来说，这可能会遇到许多情况

一种场景就是这样，

Answer 1

代码如下，您可以继续并向实体添加所需的参数。

用户实体

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import javax.persistence.Table;

@Entity
@Table(name = "USERS")
public class User {

    @Id
    @Column(name = "ID")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

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

    @OneToOne(mappedBy = "user", fetch = FetchType.LAZY)
    private Cart cart;

    public Long getId() {
        return id;
    }

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

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public Cart getCart() {
        return cart;
    }

    public void setCart(Cart cart) {
        this.cart = cart;
    }

}

cart实体

import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Column;
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.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.OneToOne;
import javax.persistence.Table;

@Entity
@Table(name = "CART")
public class Cart {

    @Id
    @Column(name = "ID")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name = "USER_ID")
    private User user;

    @ManyToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    @JoinTable(name = "CART_PRODUCT", joinColumns = @JoinColumn(name = "CART_ID") , inverseJoinColumns = @JoinColumn(name = "PRODUCT_ID") )
    private Set<Product> products;

    public Long getId() {
        return id;
    }

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

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public Set<Product> getProducts() {
        return products;
    }

    public void setProducts(Set<Product> products) {
        this.products = products;
    }

}

产品实体

import java.util.Set;

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.ManyToMany;
import javax.persistence.Table;

@Entity
@Table(name = "PRODUCT")
public class Product {

    @Id
    @Column(name = "ID")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

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

    @ManyToMany(cascade = CascadeType.ALL, mappedBy = "products")
    private Set<Cart> carts;

    public Long getId() {
        return id;
    }

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

    public String getProductName() {
        return productName;
    }

    public void setProductName(String productName) {
        this.productName = productName;
    }

    public Set<Cart> getCarts() {
        return carts;
    }

    public void setCarts(Set<Cart> carts) {
        this.carts = carts;
    }

}

Checkout该存储库是著名的Microsoft Eshoponcontainers项目的港口。 https：//github.com/harshaghanta/springboot-eshoponcontainers