mysql - SQL query to do division -

please on below sql query divide first set of query second one.

select   (   select `business_unit`,     count(`joining_month`)    `jl`    `final_status` = 'joined'     , `source_wise` = 'referral'     , `hiring_catg` in ('lateral','contract conversion')    group `business_unit` )  div  (   select `business_unit`,     count(`joining_month`) b    `jl`    `final_status` = 'joined'     , `hiring_catg` in ('lateral','contract conversion')    group `business_unit` ) ;  

the query posted dead-end; cannot made work in direction.

i try count number of rows pass condition source_wise = 'referral' , total number of rows each group , compute ratio.

the query this:

select `business_unit`,     sum(if(`source_wise` = 'referral', 1, 0)) ref     count(`joining_month`) total `jl` `final_status` = 'joined'    , `hiring_catg` in ('lateral','contract conversion') group `business_unit` 

you have compute ref/total each row in client code. or can compute directly changing query above.