ClientMtTable2 p = child.newObject(ClientMtTable2.class);
ClientMtTable1 aChild = (ClientMtTable1) Cayenne.objectForPK(
child,
a.getObjectId());
p.setGlobalAttribute("X");
aChild.addToTable2Array(p);
child.commitChangesToParent();
child.deleteObjects(p);
aChild.removeFromTable2Array(p);