Actually EclipseLink does provide a means to order the mappings. By
default however all the relational mappings are grouped together at the
same 'weight' and amoung the relational mappings the order is not defined
until set by the developer. Using a DescriptorCustomizer the mappings can
be iterated over and a weight set. A weight is just an integer between 1
and Integer.MAX_VALUE. All non-relational mappings (ie. @Basic) are
weighted at 1 so picking a number larger than 1 but less than
Integer.MAX_VALUE will insure that the back mapping is processed before
the 'forward' mapping is processed.
--Gordon