Object Query Language
Object Query Language (OQL) is a query language standard for object-oriented databases modeled after SQL and developed by the Object Data Management Group (ODMG). Because of its overall complexity the complete OQL standard has not yet been fully implemented in any software. The OQL standard influenced the design of later query languages such as JDOQL and EJB QL, though none are considered to be any version of OQL. General rules. The following rules apply to OQL statements: Examples. Simple query. The following example illustrates how one might retrieve the CPU-speed of all PCs with more  than 64MB of RAM from a fictional PC database: SELECT pc.cpuspeed FROM PCs pc WHERE pc.ram > 64; Query with grouping and aggregation. The following example illustrates how one might retrieve the average amount of RAM on a PC, grouped by manufacturer: SELECT manufacturer, AVG(SELECT part.pc.ram FROM partition part) FROM PCs pc GROUP BY manufacturer: pc.manufacturer; Note the use of the keyword codice_1, as opposed to aggregation in traditional SQL.