isPrimary

IsPrimary is a boolean flag used in software systems to indicate that an item is the primary or default among a set of related items. It is a naming convention found in data models, APIs, and user interfaces rather than a formal standardized term. When present, the isPrimary field typically holds a true value for the designated item and false for others in the same group.

Common usages include representing default or preferred elements within collections. For example, a user may have multiple contact methods (emails or phone numbers) where one entry is marked as isPrimary to denote the default contact method. In relational data, isPrimary can designate the main relation in a one-to-many association, such as the primary shipping address of a customer or the main publisher in a product’s release history.

In APIs and data interchange formats, isPrimary is often serialized as a boolean property in JSON or similar structures. Naming variations exist (primary, default), but isPrimary emphasizes a binary choice between a primary item and alternatives. Some systems enforce constraints such as “at most one item in a group may have isPrimary set to true,” while others allow multiple primaries depending on the domain.

Relation to primary keys: isPrimary is distinct from a primary key. A primary key uniquely identifies a record, whereas isPrimary marks a particular item as the default within a related set. See also primary key, default, and reference data modeling practices.