mybatis Plus 多表联合查询

//实体类package com.sk.skkill.entity;


import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data; import java.io.Serializable;
import java.util.Date;
import java.util.List; @TableName("orders")
@Data
public class Order implements Serializable
{
public static final long serialVersionUID =1L;
private String id;
private String orderName;
private Date createTime;
private Date updateTime;
private String userID; @TableField(exist = false)
private List<Users> listUsers; public Order(){ } public Order(String id, String orderName) {
this.id = id;
this.orderName = orderName;
} } //dao层
package com.sk.skkill.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.sk.skkill.entity.Order;
import com.sun.javafx.collections.MappingChange;
import org.apache.ibatis.annotations.Select; import java.util.List;
import java.util.Map; public interface OrderMapper extends BaseMapper<Order>
{
List<Order> selectOrder();
int addOrder(Order order); //多表联合查询 按条件orderID
@Select("select t1.*,t2.user_name,t2.nick_name from orders t1 LEFT JOIN users t2 ON t1.user_id =t2.id WHERE t1.user_id= #{id}")
List<Map<String,Object>> orderUserList(Page<Map<String,Object>> page,String id); }

//service层
package com.sk.skkill.service;

import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.IService;
import com.sk.skkill.entity.Order; import java.util.List;
import java.util.Map; public interface OrderService extends IService<Order>
{
List<Order> selectOrder();
int addOrder(Order order);
// List<Map<String,Object>> orderUserList(Page<Map<String,Object>> page, String id);
Page<Map<String,Object>> selectListPage(int current,int number,String id);
}
//serviceImpl层
package com.sk.skkill.service.impl;

import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.sk.skkill.entity.Order;
import com.sk.skkill.mapper.OrderMapper;
import com.sk.skkill.service.OrderService;
import org.springframework.stereotype.Service; import java.util.List;
import java.util.Map; @Service
public class OrderServiceImpl extends ServiceImpl<OrderMapper, Order> implements OrderService
{ @Override
public List<Order> selectOrder() {
return baseMapper.selectList(null);
} @Override
public int addOrder(Order order) {
return baseMapper.insert(order);
} @Override
public Page<Map<String, Object>> selectListPage(int current, int number,String id) {
//新建分页
Page<Map<String,Object>> page =new Page<Map<String,Object>>(current,number);
//返回结果
return page.setRecords(this.baseMapper.orderUserList(page,id));
} }
//controller层

 

package com.sk.skkill.controller;

import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.sk.skkill.entity.Order;
import com.sk.skkill.service.impl.OrderServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController; import java.util.List;
import java.util.Map; @RestController
@RequestMapping("order")
public class OrderController
{
@Autowired
private OrderServiceImpl service; @RequestMapping("selectOrder")
public List<Order> selectOrder()
{
return service.selectOrder();
}
@RequestMapping("addOrder")
public int addOrder(Order order){
order=new Order("FGGG","蒙牛MILK");
return service.addOrder(order); }
@RequestMapping("selectListPage")
public List<Map<String,Object>> selectListPage(String id)
{
Page<Map<String, Object>> page = service.selectListPage(1, 2,id);
return page.getRecords();
} }
 
 
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