Which expressions must be provided with an alias in a core data services view?

In the context of Core Data Services (CDS) views, an alias is a temporary name assigned to a field or expression, allowing for clearer interpretation and use in queries. When it comes to the CASE expression, it inherently generates a new column based on the conditions defined within it. Since this generated column does not have a name until explicitly given one, providing an alias is mandatory.

This makes it essential to use an alias for CASE expressions to ensure that the resulting column can be referenced appropriately in other layers of the application, such as when creating reports or further queries. Without the alias, the CASE expression would lack a recognizable identifier, leading to confusion or errors during data retrieval.

On the other hand, while cached data, currency conversion, and unit conversion may involve calculations or transformations of data, they do not specifically require an alias to be defined within a CDS view. Cached data typically refers to pre-stored retrievals which maintain their original columns. Currency and unit conversions can often be defined within the attributes of already existing fields or can be generated without direct need for an alias. Therefore, the need for an alias is particularly crucial for the CASE expression to ensure clarity and prevent ambiguity in the data model.