Hi everybody



I noticed in the EJB 2.0 specification that most of the examples use java.util.Collection when defining a relationship between two entities, even though java.util.Set is also allowed.


Why is that so?


I would expect java.util.Set to be the most frequently used type, since in general you would not want duplicates in a relationship. Think of a Person-owns-Car relationship for instance – you are not interested in any duplicates here, since a Person cannot own the same car twice so to speak (if one relationship says that person P is the owner of car C, it does not provide you with any usefull information to create yet another relationship between P and C).


Which cmr-field-types do you use and why?





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