在写东西的过程中，多表联查和分页功能必不可少。当然，crud也很重要,MyBatis-Plus一款国产的框架。优化了许多操作，但大部分文档都记录的是单表操作，多表join在很多场景用的很多，本次主要记录一下，多表联查和分页的使用。

Pom.xml    
　　　　<dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.0.7.1</version>
        </dependency>

//MybatisPlusConfig

Spring boot方式

@Configuration
@MapperScan("com.qy.site")
public class MybatisPlusConfig {
    // 最新版
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.H2));
        return interceptor;
    }
}

mapper接口

public interface OrderExpressMapper extends BaseMapper<OrderExpressEntity> {
    Page<OrderExpressEntity> findAllAndPage(Page<OrderExpressEntity> page);
}

mapper  Xml

<select id="findAllAndPage" resultType="com.qy.site.modules.base.entity.OrderExpressEntity">

  SELECT e.*,o.orderNo FROM yz_order_express e JOIN yz_orders o ON e.orderId=o.orderId

</select>

controller

public String expressList(ModelMap model, HttpServletRequest request,int page,int limit){
    Page<OrderExpressEntity> pageArt=new Page<OrderExpressEntity>(page,limit);
    Page<OrderExpressEntity> page1 = orderExpressMapper.findAllAndPage(pageArt); //自定义方法，多表
    int total = (int)page1.getTotal();
    List<OrderExpressEntity> orderList=page1.getRecords();
    Map<String,Object> map=new HashMap<>();
    map.put("list",orderList);
    map.put("total",total);
    System.out.println(map);
    model.addAttribute("orderList",orderList);
    return "admin/order/index";
}