CQL++: A SQL for the Ode Object-Oriented DBMS

Shaul Dar, Narain H. Gehani, H. V. Jagadish

Abstract: CQL++ is a declarative front end to the Ode object-oriented database. It combines a SQL-like syntax with the C++ class model. CQL++ provides facilities for defining classes, and for creating, querying, displaying, and updating objects. Classes and objects created using CQL++ can freely be intermixed with those created using O++, the primary programming language of Ode. CQL++ gives its users a relatively straightforward interface, by hiding from them such O++ details as object-ids, public and private members of objects, and the implementations (bodies) of member functions. CQL++ is based on an object algebra that preserves the closure property of SQL. CQL++ queries operate upon sets of objects and return sets of objects. CQL++ supports a rich collection of set types to maximize functionality and expressive power. CQL++ allows the user to define new classes, which can include computed attributes and make use of multiple inheritance. The user can supply default and null values for attributes, and indicate how class objects are to be displayed.