1.引入依赖

             
                 
      
       tk.mybatis
                  
      
       mapper-spring-boot-starter
              
     

2.定义mapper接口

public interface CategoryMapper extends Mapper
     
       {}
     

3.启动类添加包扫描注解

@MapperScan("com.viuman.item.mapper")

或者在每个mapper接口上都加

@org.apache.ibatis.annotations.Mapper

4.基本查询

Category category = new Category();        category.setParentId(pid);        return categoryMapper.select(category);