Elasticsearch nested sorting

Question

I'm trying to do nested sorting in Elasticsearch but so far didn't succeed.

My data structure:

{ "_id" : 1,
"authorList" : [
  {"lastName":"hawking", "firstName":"stephan"},
  {"lastName":"frey", "firstName":"richard"}
]
}

{ "_id" : 2,
"authorList" : [
  {"lastName":"roger", "firstName":"christina"},
  {"lastName":"freud", "firstName":"damian"}
]
}

I want to sort the documents according the first authors last name in the documents.

Used mapping:

"authorList" : { "type" : "nested", "properties" : {"lastName":{"type":"keyword"}}}

Sort using SearchRequestBuilder (JAVA):

    searchRequestBuilder.addSort(
SortBuilders.fieldSort("authorList.lastName")
.order(SortOrder.ASC)
.sortMode(SortMode.MIN)
.setNestedPath("authorList")
)

This works but doesn't give the wanted result (e.g. first "hawking" then "roger").

Did I missed something? Is there a way to indicate Elasticsearch to access index=0 of the array authorList? Is there any mapping / normalizer to index the first entry of the array separately?

Elasticsearch nested sorting

1 Answers