categoryId

CategoryId is an identifier used in data models and software systems to uniquely identify a category within a taxonomy. It is typically a stable value assigned to a category and used to link items to their categories and to support efficient querying, filtering, and reporting.

In relational databases, categoryId is commonly the primary key of a Category table and a foreign key in tables that store products, articles, or other items. It may be an integer, a UUID, or another string type. Some designs use natural keys, but surrogate keys like integers or GUIDs are common to preserve stability when a category's name changes.

E-commerce and content management systems use categoryId to organize catalogs and content. Categories can be arranged in hierarchies, with parent–child relationships, allowing retrieval of all descendants or products within a category using the categoryId as the anchor. This enables efficient grouping and navigation in user interfaces and back-end processes.

APIs and data interchange use categoryId as a parameter or field to assign or filter by category. Examples include queries such as /api/products?categoryId=123 or responses that include a categoryId field alongside the category name.

Design considerations include keeping categoryId immutable, ensuring referential integrity, and indexing categoryId for performance. Approaches vary on how to model hierarchies (adjacency list, path, nested sets, or closure tables). Variants include numeric IDs, UUIDs, or human-friendly slug variants; some systems expose both id and name for user interfaces, maintaining a mapping table that relates categoryId to category metadata such as name, description, and path.