How to write sql to do one aggregation over another - sql

Question

Sample data
WITH
tbl AS
(
Select 'UK' "CUST_GRP", '00001' "CUST_ID", 'John' "CUST_NAME", '001' "ORDER_ID", 'Beer' "GOODS" From Dual Union All
Select 'ITA' "CUST_GRP", '00002' "CUST_ID", 'Jack' "CUST_NAME", '002' "ORDER_ID", 'Coca Cola' "GOODS" From Dual Union All
Select 'ITA' "CUST_GRP", '00002' "CUST_ID", 'Jack' "CUST_NAME", '003' "ORDER_ID", 'Fanta' "GOODS" From Dual Union All
Select 'ITA' "CUST_GRP", '00003' "CUST_ID", 'Lisa' "CUST_NAME", '004' "ORDER_ID", 'Beer' "GOODS" From Dual Union All
Select 'ITA' "CUST_GRP", '00003' "CUST_ID", 'Lisa' "CUST_NAME", '005' "ORDER_ID", 'Coffee' "GOODS" From Dual Union All
Select 'FRA' "CUST_GRP", '00004' "CUST_ID", 'Messi' "CUST_NAME", '006' "ORDER_ID", 'Wine' "GOODS" From Dual Union All
Select 'FRA' "CUST_GRP", '00004' "CUST_ID", 'Messi' "CUST_NAME", '007' "ORDER_ID", 'Juice' "GOODS" From Dual Union All
Select 'FRA' "CUST_GRP", '00004' "CUST_ID", 'Messi' "CUST_NAME", '008' "ORDER_ID", 'Beer' "GOODS" From Dual Union All
Select 'FRA' "CUST_GRP", '00005' "CUST_ID", 'Mary' "CUST_NAME", '009' "ORDER_ID", 'Wine' "GOODS" From Dual Union All
Select 'FRA' "CUST_GRP", '00005' "CUST_ID", 'Mary' "CUST_NAME", '020' "ORDER_ID", 'Else' "GOODS" From Dual
)
I need to know the number of customers that have done the same number of orders.
Expected result should be either
TEXT
the amount of customers who ordered 1 times is 1
the amount of customers who ordered 2 times is 3
the amount of customers who ordered 3 times is 1
OR
Orders
Customers
1
1
2
3
3
1
Anyone can tell me how to write this SQL ?

Answer 1

This will get you the desired results. You are grouping by customer to find out how many orders they placed. Then grouping that subset as well.
select orders, count(*) customers
from (
select cust_id, count(*) orders
from tbl
group by cust_id
)
group by orders