问如何找到AVG给出了一些说明SQL

EN

   select m.name market_name,
           100*round(count(w.employee_id)::decimal/
                (select count(employee_id) from employee ),2)
            as "Avg Percent of Emp. Per Market"
      from workson w
      left join market m on ( m.market_id = w.market_id )
    where m.name = 'IKEA' 
    group by m.name;

select m.name as "Market Name",
   avg(w.employee_id) as "Avg.NumberofEmployeesPerMarket"
from workson w
left join employee e on ( e.employee_id = w.employee_id )
left join market m on ( m.market_id = w.market_id )
group by m.name;