Demo: Things in Hierarchies (w/o RM/SQL)

// Create god and persons

CREATE2 *god.cls = thing;
CREATE2 *person.cls = thing;
CREATE2 *adam.cls = person;
CREATE2 *eve.cls = person;
CREATE2 *john.cls = person;
CREATE2 *mary.cls = person;

// Create god's children hierarchy

CREATE2 god.child = adam;
CREATE2 god.child = eve;
CREATE2 adam.child = john;
CREATE2 adam.child = mary;
CREATE2 eve.child = john;
CREATE2 eve.child = mary;

// Create universe and planets

CREATE2 *universe.cls = thing;
CREATE2 *planet.cls = thing;
CREATE2 *mars.cls = planet;
CREATE2 *venus.cls = planet;

// Create universe's part hierarchy

CREATE2 universe.part = mars;
CREATE2 universe.part = venus;
CREATE2 mars.part = john;
CREATE2 venus.part = mary;

// Traverse god's children recursively

SELECTR god.child;

// Traverse god's distinct children recursively
SELECTRD god.child;

// Traverse universe's parts recursively
SELECTR universe.part;

// Find persons whose parent is adam and is part of mars.
// Finds john

SELECT2 %.cls=person & %.parent=adam & mars.part=%;

// Find persons whose parent is eve and is part of a planet.
// Finds john and mary

SELECT2 %.cls=person & %.parent=eve & (planet.inst=%).part=%;
SELECT2 %.cls=person & %.parent=eve & (%.cls=planet).part=%;
SELECT2 %.cls=person & %.parent=eve & %.asm=(%.cls=planet);

// Find john and mary with various queries
SELECT2 %.cls=person & eve.child=%;
SELECT2 eve.child=% & %.cls=person;
SELECT2 %.cls=person & %.parent=eve;
SELECT2 %.parent=eve;
SELECT2 eve.child=%;

// Find persons whose parent's parent is god
// and the person is part of any planet
SELECT2 %.cls=person & %.parent=(%.parent=god) & (%.cls=planet).part=%;

Note: cls/inst are abbreviations for class/instance. asm/part are abbreviations for assembly/part. Received on Tue Nov 02 2004 - 05:22:21 CET