Qualifier Expression

[Joe Baldwin]

I am attempting to create the simplest Cayenne-expedient method of  
doing the following query. (I can easily do this in SQL but am a tad  
confused with the Cayenne Expression method.)

I have an Entity (E1) with a one to one relationship with a second  
entity (E2).  I would like to perform a SELECT Query with a filter on  
one of the fields of the relationship-entity (E2.F1) and return a list  
of the first entity (E1List).

What is the most efficient Cayenne way to do this?  (I am still a bit  
confused concerning how to construct efficient queries in the object  
domain vs the relational domain.)

Thanks,
Joe