-- cityid is coming from two tables, use different case than in the file | |
select cust_id, | |
count(Cust_Id) | |
from | |
( | |
select * | |
from | |
( | |
select a.CustomerID, | |
b.NAME | |
from `customer.json` a, | |
`city.json` b | |
where | |
a.cityid = b.CITYID | |
order by | |
a.customerid | |
) as dt(cust_id, name) | |
) | |
group by | |
cust_id | |
having | |
count(cust_id) = 1 | |
order by | |
CUST_ID; |