Using SQL with object-oriented databases

摘要

We investigate how the standard database query language SQL can be extended to deal with the newly emerging trends of complex objects and object orientation. Our main concern is to extend SQL as naturally as possible, rather than to redesign SQL into “yet another” object-oriented query language. We achieve this goal through a faithful mapping from a complete object-oriented database model, compatible with recent proposals in the field, to the nested relational database model, which is widely accepted as a natural extension of the relational database model on which standard SQL is based. We provide formal definitions of syntax and semantics. We also review related research and situate our work into it.