(Object Query Language) A query language that supports complex data types (multimedia, spatial, compound documents, etc.) that are stored as objects. Defined by the ODMG, it is a superset of the SQL-92 query language. Standard SQL queries can still be used, and the OQL server process converts the objects into relational views.

OQL also supports the OMG's object model (OM), allowing queries to be made against CORBA objects. In addition, OQL commands can be embedded in URL links that are sent to an OQL gateway by the HTTP server. The results are converted back into Web pages for the user.