Expression to compare a property against another property

Is there a facility in Cayenne to create an expression that would compare a property of one object against another property (maybe via a relationship path rooted at the same object) rather than against a scalar value? 

I’m trying to port over some old EOF code and we used to have a EOKeyComparisonQualifier which would allow you to create a qualifier to compare a property’s value with that of another property (or property key path). 

For example, given a model consisting of employees, where each employee can have a relationship to a manager and each employee has a salary property, you could use a key comparison qualifier to find those employees that are making more than their manager:

	salary > manager.salary

I’ve looked in ExpressionFactory and through some of the source, but to me it looks like all comparison nodes in an expression operate on a key and a scalar. Am I missing something?

Thanks for any help or pointers,

F

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Faizel Dakri