mysql不同条件下的统计

不同条件下的统计：

 

SELECT  IFNULL(CONCAT(ROUND(normalnum/allnum*100,2), '%' ),'0.00%') as normrate,
        IFNULL(CONCAT(ROUND(abnormalnum/allnum*100,2), '%' ),'0.00%') as abnormrate
from (
   select 
    SUM(IF(current_status  = null,0,1)) as allnum,
    SUM(IF(current_status  = 4,1,0)) as normalnum,
    SUM(IF(current_status  = 4,0,1)) as abnormalnum
   from imsrobot
)a