Object-relational mapping systems have become often-used tools to provide application access to relational databases. In a database-first development scenario, the onus is on the developer to construct a meaningful object layer for the application because shipping tools, as ORM tools only ship database reverse-engineering tools that generate objects with a trivial one-to-one mapping. We built a tool, EdmGen++, that combines pattern-finding rules from conceptual modeling literature with configurable conditions that increase the likelihood that found patterns are semantically relevant. EdmGen++ produces a conceptual model with inheritance in Microsoft’s Entity Data Model, which Microsoft’s Entity Framework uses to support an executable object-to-relational mapping. The execution time of EdmGen++ on customer databases is reasonable for design-time.