Elasticsearch-2.0 parent-chid query returning empty results

[zzalyp]

I am using Elasticsearch version 2.0.0, query parent-child, but the result is empty, I do not know where the problem is, I refer to this examplehttps://stackoverflow.com/questions/29116935/elastic-search-parent-child-data-search-java-api

PUT bookstore
{
   "mappings": {
      "author": {
         "properties": {
            "authorname": {
               "type": "string"
            }
         }
      },
      "book": {
         "_parent": {
            "type": "author"
         },
         "properties": {
            "bookname": {
               "type": "string"
            }
         }
      }
   }
}

add two authors:

PUT bookstore/author/1
{
   "authorname": "author1"
}

PUT bookstore/author/2
{
   "authorname": "author2"
}

add two books of author author1:

PUT bookstore/book/11?parent=1
{
   "bookname": "book11"
}

PUT bookstore/book/12?parent=1
{
   "bookname": "book12"
}

add two books of author author2:

PUT bookstore/book/21?parent=2
{
   "bookname": "book21"
}

PUT bookstore/book/22?parent=2
{
   "bookname": "book22"
}

search result enter

Ordinary query no problementer