OQL is a query language created in 1986.
|#1630on PLDB||37Years Old||245Users|
Object Query Language (OQL) is a query language standard for object-oriented databases modeled after SQL. OQL was developed by the Object Data Management Group (ODMG). Because of its overall complexity nobody has ever fully implemented the complete OQL. Read more on Wikipedia...
select c.address from Persons p, p.children c where p.address.street = "Main Street" and count(p.children) >= 2 and c.address.city != p.address.city