vaaibhavmohan

select A.country,count(A.CustomerID) as N
from 
     (select country,Count(CustomerID) as N1 from customers group by country) as A
left join 
    (select country,Count(CustomerID) as N2 from customers group by country) as B 
     on A.N1=B.N2

the error:it is not reading A.customerid