MultipleAttribute

MultipleAttribute is a term used to describe an attribute that can hold multiple values for a single entity or object. It is not a formal standalone construct, but a concept that appears in data modeling, programming, and configuration contexts. In practice, it denotes a single logical attribute with a collection of values rather than a single scalar value.

In data modeling, multivalued attributes appear in ER diagrams as attributes that can have many values for a given entity, such as the set of phone numbers associated with a person. Most modeling approaches require converting multivalued attributes into separate relations or tables to satisfy normalization rules, typically by creating a separate relation with a foreign key back to the entity.

In programming and software design, multiple attributes are often represented as collection properties such as lists, arrays, or sets. An object may expose a property that stores several values of a given type, or an ORM may map a multi-valued attribute to a related table. This approach preserves the one-to-many relationship and makes operations like add, remove, or iterate straightforward.

Considerations for implementing multiple attributes include data validation to enforce value constraints, consistency across persistence layers, indexing for efficient queries, and serialization strategy for storage or network transfer. Careful schema evolution is required to avoid breaking changes when the number or type of values changes.

Related concepts include multivalued attributes, collections in programming languages, and attribute normalization in databases.