Order Count Distribution

SQL practice question · Medium · Aggregation · Walmart

customer_orders has one row per purchase (user_id, purchase_id). Count the purchases of each user, then for each purchase count return how many users made exactly that many purchases. Output columns: purchase_count, users_num. Order by purchase_count ascending.

Table: customer_orders

Schema of customer_orders
Column	Type
user_id	INTEGER
purchase_id	INTEGER

Schema of customer_orders

Column

Type

user_id

INTEGER

purchase_id

INTEGER

Sample rows of customer_orders
user_id	purchase_id
1	10
1	11
1	12
2	13
3	14
3	15

Sample rows of customer_orders

user_id

purchase_id

Expected output on the sample data
purchase_count	users_num
1	1
2	1
3	1

Expected output on the sample data

purchase_count

users_num

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