Practice SQL Window Functions | Xorthax's Trading Post

Tables Used

orderdetails

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

orders

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

products

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

Expected Output

Column
category
productname
previousproduct

58. Reverse Product Lineage

Track each product sold in reverse, showing its category and the item before it.

Xorthax wants to track the sequence of products sold in reverse. Write a query to display the current product and the previous product sold in each category.

Write Your Query