orderitems

An order item, often called a line item, is a record that represents a single product or service contained in a customer's order. It sits as a child of the order and links to the catalog entry or product. Order items capture the quantities ordered, pricing, discounts, taxes, and the extended line total for that item, and they support fulfillment and revenue calculations.

In relational data models, an order_items table stores one row per item. Typical fields include item_id (or id), order_id (foreign key to orders), product_id (foreign key to products), quantity, unit_price, discount_amount, tax_amount, and line_total. The primary key is often an auto-increment item_id, or a composite key of (order_id, product_id). Prices may be stored at the time of ordering to preserve historical accuracy.

Order items are linked to both orders and products. The system aggregates line_totals to form the order total, while fulfillment processes may reference each item to allocate stock and generate shipments. Some architectures track additional attributes such as sku, product_name, variant options, and warehouse or fulfillment status at the item level.

Terminology varies by platform. Some systems use line_items or order_lines instead of order_items. For configurable products, an order item may reference a specific product variant and store option values. Currency, tax rules, and discounts can differ between items, so item-level data helps preserve accurate accounting and analytics.

Common use cases include calculating revenue, analyzing item performance, processing refunds and returns, and auditing orders. Data integrity constraints typically enforce non-negative quantities, valid foreign keys, and consistency between unit_price, line_total, and discounts. Indexes on order_id and product_id improve query performance for reporting and fulfillment workflows.