小编pc_*_*pyr的帖子

桌子：

Date            Id       Value                    
2019-02-09      a1       ab            
2019-01-12      a2       cd
2019-12-12      a1       ab
2017-07-23      a1       ab
2018-12-09      a1       ab
2018-12-28      a1       cd
2016-11-09      a2       cd
2016-05-19      a2       ab

输出：

      Id        Max-Min               
      a1        1     
      a2       -1   

目的是创造Max_year_count-Min_year_count per Id.
例如，计算Value column：
(count of occurrence of value in max_year with group by Id)-(count of occurrence of value in min_year with group by Id)
谢谢！！