OCL2PSQL: An OCL-to-SQL Code-Generator for Model-Driven Engineering

The Object Constraint Language (OCL) is a textual, declarative language typically used as part of the UML standard for specifying constraints and queries on models. Several attempts have been proposed in the past for translating OCL expressions into SQL queries in the context of Model Driven Engineering (MDE). To cope with OCL expressions that include iterators, previous attempts resorted to imperative features (loops, cursors) of SQL, with the consequent loss of efficiency. In this paper, we define (and implement) a novel mapping from OCL to SQL that covers (possibly nested) iterators, without resorting to imperative, non-declarative features of SQL. We show with a preliminary benchmark that our mapping generates SQL queries that can be efficiently executed on mid- and large-size SQL databases.