數據表與簡單java類——多對多映射

給定一張Meber和Product表,獲得以下信息:java

1.獲取一個用戶訪問的全部商品信息c++

2.獲取一個商品被哪些用戶瀏覽過的信息app

package Mapping_transformation;

class Meber
{
    private String name ;
    private int age ;
    private Product products[] ;           //一我的瀏覽多個商品
    public Meber(String name , int age)
    {
        this.name = name ;
        this.age = age ;
    }
    public void setProducts(Product products[] )
    {
        this.products = products ;
    }
    public Product[] getProducts()
    {
        return products ;
    }
    public String getInfo()
    {
        return "【用戶信息】姓名:"+this.name + "年齡:"+this.age ;
    }
}
class Product
{
    private String name ;
    private double price ;
    private Meber mebers[] ;                    //一個商品被多我的瀏覽
    public Product(String name ,double price)
    {
        this.name = name ;
        this.price = price ;
    }
    public String getInfo()
    {
        return "【商品信息】名稱:"+this.name + "價格:"+this.price ;
    }

    public void setMebers(Meber[] mebers) {
        this.mebers = mebers;
    }

    public Meber[] getMebers() {
        return mebers;
    }
}
public class Many_to_many {
    public static void main(String[] args) {
        //設置關係
        Meber meberA = new Meber("小兔子",35);                    //設置兩個用戶
        Meber meberB = new Meber("小白喵",20);
Product proA
= new Product("c++從入門到放棄",50.00); //設置三個商品 Product proB = new Product("java從入門到放棄",49.00); Product proC = new Product("C語言從入門到放棄",46.00);
meberA.setProducts(
new Product[]{proA,proB}); //設置用戶瀏覽過的商品 meberB.setProducts(new Product[]{proA,proC});
proA.setMebers(
new Meber[]{meberA}); proB.setMebers(new Meber[]{meberA,meberB}); //設置商品被瀏覽的用戶 proC.setMebers(new Meber[]{meberB}); //獲取數據 System.out.println("-----------------根據用戶查看瀏覽商品信息--------------------"); System.out.println(meberA.getInfo()); for(int i = 0 ; i<meberA.getProducts().length ;i++) { System.out.println("\t|-"+meberA.getProducts()[i].getInfo()); } System.out.println("-----------------根據被瀏覽的商品查看用戶--------------------"); System.out.println(proA.getInfo()); for(int i = 0 ; i< proA.getMebers().length ; i++) { System.out.println("\t|-"+proA.getMebers()[i].getInfo()); } } }
result:
-----------------根據用戶查看瀏覽商品信息-------------------- 【用戶信息】姓名:小兔子年齡:35 |-【商品信息】名稱:c++從入門到放棄價格:50.0 |-【商品信息】名稱:java從入門到放棄價格:49.0 -----------------根據被瀏覽的商品查看用戶-------------------- 【商品信息】名稱:c++從入門到放棄價格:50.0 |-【用戶信息】姓名:小兔子年齡:35
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