Practice SQL Window Functions | Xorthax's Trading Post

Tables Used

orders

Column	Type
orderid	bigint
customerid	bigint
orderdate	timestamp without time zone
totalamount	double precision
status	text

orderdetails

Column	Type
orderdetailid	bigint
orderid	bigint
productid	bigint
quantity	bigint
unitprice	double precision
currencyid	bigint

products

Column	Type
productid	bigint
name	text
description	text
category	text
price	double precision
supplierid	bigint
stockquantity	bigint

Expected Output

Column
category
start_week
end_week
streak_length

80. The Merchant’s Marathon

Xorthax wants to know which categories endured the long run of commerce without faltering.

Xorthax wants to see which product categories sell steadily. For each category, find the longest streak of consecutive weeks where at least 10 completed orders in that category was sold. Include the start of the first week and start of the last week in the result set

Write Your Query

SQL Cookbook (O’Reilly)

Practical SQL recipes for real-world querying—great complement to hands-on practice.

(Affiliate link – as an Amazon Associate I earn from qualifying purchases.)