您可以通过这种方式将“mm/dd/yyyy”转换为“yyyy-mm-dd”。

select TO_DATE(FROM_UNIXTIME(UNIX_TIMESTAMP(StartDate, 'dd/MM/yyyy'))) as month
from your_table;

分组（月和部门）

select 
  MONTH(TO_DATE(FROM_UNIXTIME(UNIX_TIMESTAMP(StartDate, 'dd/MM/yyyy')))) as month,
  Department,
  sum(Tripduration) --or avg or whatever you want
from your_table
group by MONTH(TO_DATE(FROM_UNIXTIME(UNIX_TIMESTAMP(StartDate, 'dd/MM/yyyy')))), Department;