Compute Total Cost from Two Tables (SQL Aggregation + Join) with Tiered Fees Follow-up

Problem: Calculate Total Cost Using Two Tables (with a Tiered Fee Follow-up) You have two relational tables that together determine the total_cost of every order. Table schemas Table 1: order_items Column Type Meaning order_id int Identifier of the order item_id int Identifier of the item or product quantity int Number of units purchased unit_price decimal Price of one unit Table 2: order_fees Column Type Meaning order_id int Identifier of the order fee_type string Category…