Which statement about data relationships is correct?

The statement that an Entity must have an identifier to allow relationships is correct because identifiers serve as unique keys for each record within an entity. In the context of a relational database or an OutSystems application, having a unique identifier is crucial for defining relationships between entities, such as one-to-one, one-to-many, or many-to-many associations. These identifiers enable the framework to track entities accurately and enforce data integrity.

In relational data models, identifiers facilitate the linking of different entities, allowing for effective data retrieval and manipulation. Without a unique identifier, it would be challenging to establish clear and reliable connections between different pieces of data, which could lead to confusion and errors in operations involving relationships.

This principle underscores the importance of defining a proper schema when working with data relationships in applications built using OutSystems, ensuring that each entity is uniquely identifiable to support complex interactions among data structures.