逐年显示表中的记录

Question

select station_id,count(case_id) from emer_complaint group by station_id

上面的查询返回正确的结果。但是，当我尝试此查询以显示年度记录时。然后显示错误ORA-00904: "YEAR": invalid identifier

select year(date_time)
      ,count(case_id) 
 from emer_complaint  
group by year(date_time);

date_time 的数据类型是Timestamp。

先谢谢了！！

Answer 1

select to_char(date_time, 'YYYY'), count(case_id)
from   emer_complaint
group by to_char(date_time, 'YYYY');