MyBatis实现一对多多层Collection集合嵌套关系实现

package com.cn.fb.utils;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;


public class MybatisUtils {

    private static SqlSessionFactory sqlSessionFactory = null;
    private static final ThreadLocal t = new ThreadLocal<>();

    static {
        try {
            InputStream is = Resources.getResourceAsStream("mybatis-config.xml");
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    
    public static SqlSession openSession() {
        SqlSession sqlSession = t.get();
        if (sqlSession == null) {
            sqlSession = sqlSessionFactory.openSession();
            t.set(sqlSession);
        }
        return sqlSession;
    }

    
    public static void closeSqlSession() {
        SqlSession sqlSession = t.get();
        if (sqlSession != null) {
            sqlSession.close();
            t.remove();
        }
    }

    
    public static void commit() {
        SqlSession sqlSession = openSession();
        sqlSession.commit();
        closeSqlSession();
    }

    
    public static void rollback() {
        SqlSession sqlSession = openSession();
        sqlSession.rollback();
        closeSqlSession();
    }

    
    public static  T getMapper(Class clazz) {
        SqlSession sqlSession = openSession();
        return sqlSession.getMapper(clazz);
    }
}

UsersEntity

package com.cn.fb.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;
import java.util.Date;
import java.util.List;


@Data
@AllArgsConstructor
@NoArgsConstructor
public class UsersEntity implements Serializable {
    private Integer userId;
    private String userName;
    private String password;
    private String nickName;
    private String realName;
    private String userImg;
    private String userMobile;
    private String userEmail;
    private String userSex;
    private Date userBirth;
    private Date userRegisterTime;
    private Date userUpdateTime;
    private List ordersEntityList;
}

OrdersEntity

package com.cn.fb.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;
import java.math.BigDecimal;
import java.util.Date;
import java.util.List;


@Data
@AllArgsConstructor
@NoArgsConstructor
public class OrdersEntity implements Serializable {
    private String orderId;
    private Integer userId;
    private String untitled;
    private String receiverName;
    private String receiverMobile;
    private String receiverAddress;
    private BigDecimal totalAmount;
    private BigDecimal actualAmount;
    private Integer payType;
    private String orderRemark;
    private Integer status;
    private String deliveryType;
    private String deliveryNum;
    private BigDecimal orderFreight;
    private Integer deleteStatus;
    private Date createTime;
    private Date updateTime;
    private Date payTime;
    private Date deliveryTime;
    private Date finishTime;
    private Date cancelTime;
    private Integer closeType;
    private List ordersDetailsEntityList;
}

OrdersDetailsEntity

package com.cn.fb.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;
import java.math.BigDecimal;
import java.util.Date;


@Data
@AllArgsConstructor
@NoArgsConstructor
public class OrdersDetailsEntity implements Serializable {
    private Integer id;
    private String orderId;
    private Integer productId;
    private String productName;
    private String productImg;
    private BigDecimal productPrice;
    private Integer count;
    private BigDecimal totalAmount;
    private Date buyTime;
    private Integer commentStatus;
}

mybatis-config.xml

    
        
        
        
        
        
        
        
        
        
        
        
        
        
            
            
            
            
            
            
            
            
            
            
            
            
            
            
            
            
            
            
            
            
            
            
            
                
                
                
                
                
                
                
                
                
                
            
        
    

    
        SELECT u.user_id,
               u.username,
               u.PASSWORD,
               u.nickname,
               u.realname,
               u.user_img,
               u.user_mobile,
               u.user_email,
               u.user_sex,
               u.user_birth,
               u.user_regtime,
               u.user_modtime,
               o.order_id,
               o.user_id,
               o.untitled,
               o.receiver_name,
               o.receiver_mobile,
               o.receiver_address,
               o.total_amount,
               o.actual_amount,
               o.pay_type,
               o.order_remark,
               o.STATUS,
               o.delivery_type,
               o.delivery_num,
               o.order_freight,
               o.delete_status,
               o.create_time,
               o.update_time,
               o.pay_time,
               o.delivery_time,
               o.flish_time,
               o.cancel_time,
               o.close_type,
               d.id,
               d.order_id,
               d.product_id,
               d.product_name,
               d.product_img,
               d.product_price,
               d.count,
               d.total_amount,
               d.buy_time,
               d.comment_status
        FROM users u
                 LEFT JOIN orders o ON u.user_id = o.user_id
                 LEFT JOIN orders_details d ON o.order_id = d.order_id
    

    
        
        where u.user_id = #{userId};