Inventory Management Schema

Tables

products

• product_id (PRIMARY KEY)
• product_name
• sku
• category
• unit_cost
• reorder_point (minimum stock level before reordering)
• discontinued (boolean)

warehouses

• warehouse_id (PRIMARY KEY)
• warehouse_name
• location
• capacity

inventory

• inventory_id (PRIMARY KEY)
• product_id (FOREIGN KEY -> products)
• warehouse_id (FOREIGN KEY -> warehouses)
• quantity_on_hand
• last_updated

stock_movements

• movement_id (PRIMARY KEY)
• product_id (FOREIGN KEY -> products)
• warehouse_id (FOREIGN KEY -> warehouses)
• movement_type (inbound/outbound/transfer/adjustment)
• quantity (positive for inbound, negative for outbound)
• movement_date
• reference_number

Business Logic

Available stock: quantity_on_hand from inventory where quantity_on_hand > 0

Products needing reorder: total quantity_on_hand across warehouses <= product's reorder_point

Active products only: Exclude discontinued = true unless analyzing discontinued items

Example Query

-- Find products below reorder point
SELECT p.product_id, p.product_name, p.reorder_point, SUM(i.quantity_on_hand) as total_stock
FROM products p
JOIN inventory i ON p.product_id = i.product_id
WHERE p.discontinued = false
GROUP BY p.product_id, p.product_name, p.reorder_point
HAVING SUM(i.quantity_on_hand) <= p.reorder_point;