What must every entity contain according to OutSystems entity requirements?

In OutSystems, every entity must contain an identifier attribute, also known as a primary key. This identifier is essential because it uniquely distinguishes each record within that entity. The presence of a unique identifier ensures that operations such as retrieval, updating, and deleting records can be performed accurately without ambiguity. This requirement lays the foundation for entity integrity and allows for effective referencing in relationships between entities, ensuring the database maintains its structure even as it scales or as data changes over time.

While entities may have relationships, defined attributes, or multiple attributes, these are not mandatory requirements for the existence of an entity in OutSystems. The critical aspect is the identifier, as it serves as the backbone for the entity's functionality and data management within the application.