Abstract
We apply recent work on referring expression types to the issue of identification in Conceptual Modelling. In particular, we consider how such types yield a separation of concerns in a setting where an Information System based on a conceptual schema is to be mapped to a relational schema plus SQL queries. We start from a simple object-centered representation (as in semantic data models), where naming is not an issue because everything is self-identified (possibly using surrogates). We then allow the analyst to attach to every class a preferred “referring expression type”, and to specify uniqueness constraints in the form of generalized functional dependencies. We show (1) how a number of well-formedness conditions concerning an assignment of referring expressions can be efficiently diagnosed, and (2) how the above types attached to classes allow a concrete relational schema and SQL queries over it to be derived from a combination of the conceptual schema and queries over it.