Breezejs projection not working for referencing one to many navigators

Question

I have the following model: 1 Person to many Participant ('enrollments' is the navigator)

If I just want the name of the person, and the date of all enrollments, this doesn't work:

EntityQuery.from('Person').where('id','eq',id)
           .select('firstName, lastName, enrollments.dateEnrolled')
           .execute()

I get an error:

 Unable to locate property 'DateEnrolled' on type 
'System.Collections.Generic.ICollection`1[EntityClasses.Participant]'

What is the proper syntax for projections of fields on one-to-many relationships?

Answer 1

There is no really good way to express this in a single query. You can get all of the "enrollments" but you will need to select out the "dateEnrolled" on the client.

EntityQuery.from('Person').where('id','eq',id)
       .select('firstName, lastName, enrollments').expand("enrollments")
       .execute().then(function(data) {
       // extract "dateEnrolled" from data.results
});

Alternatively, you can use a 'named query" on the server that performs the projection there and simply query the projection from the client.

Or perhaps better would be to invert your query. Something like this: ( assuming you have a scalar property named 'Person' on your 'Enrollment' type).

EntityQuery.from('Enrollments').where('person.id','eq',id)
       .select('person.firstName, person.lastName, dateEnrolled').expand("person")
       .execute().then(...);