例子：

SELECT

str_to_date(concat(year(a.tb_time),

date_format(a.tb_time,

'%m'),

'01'),

'%Y%m%d') tb_time,

cast(a.category_id as char) category_id,

a.category_name,

sum(a.tendered_sum)/sum(a.winbid) tendered_sum,

sum(a.winbid_sum)/sum(a.winbid) winbid_avg

from

( SELECT

a.tb_time,

a.category_id,

a.category_name,

a.tendered_sum,

a.winbid_sum,

case

when a.winbid_is = 'X'

and a.callbid_result = '授标结束' then '1'

else '0'

end winbid

from

v_bid_information a ) a

GROUP BY

year(a.tb_time),

month(a.tb_time),

a.category_id,

a.category_name