Field relationship

• join type for parent-child field relationship
• franchise is the parent, film is the child

{
  "mappings": {
    "properties": {
      "film_to_franchise": {
        "type": "join",
        "relations": {
          "franchise": "film"
        }
      }
    }
  }
}

Bulk import for parent-child relationship

{ "create" : { "_index" : "series", "_id" : "1", "routing" : 1} }
{ "id": "1", "film_to_franchise": {"name": "franchise"}, "title" : "Star Wars" }
{ "create" : { "_index" : "series", "_id" : "260", "routing" : 1} }
{ "id": "260", "film_to_franchise": {"name": "film", "parent": "1"}, "title" : "Star Wars: Episode IV - A New Hope", "year":"1977" , "genre":["Action", "Adventure", "Sci-Fi"] }
{ "create" : { "_index" : "series", "_id" : "1196", "routing" : 1} }
{ "id": "1196", "film_to_franchise": {"name": "film", "parent": "1"}, "title" : "Star Wars: Episode V - The Empire Strikes Back", "year":"1980" , "genre":["Action", "Adventure", "Sci-Fi"] }
{ "create" : { "_index" : "series", "_id" : "1210", "routing" : 1} }
{ "id": "1210", "film_to_franchise": {"name": "film", "parent": "1"}, "title" : "Star Wars: Episode VI - Return of the Jedi", "year":"1983" , "genre":["Action", "Adventure", "Sci-Fi"] }
{ "create" : { "_index" : "series", "_id" : "2628", "routing" : 1} }
{ "id": "2628", "film_to_franchise": {"name": "film", "parent": "1"}, "title" : "Star Wars: Episode I - The Phantom Menace", "year":"1999" , "genre":["Action", "Adventure", "Sci-Fi"] }
{ "create" : { "_index" : "series",  "_id" : "5378", "routing" : 1} }
{ "id": "5378", "film_to_franchise": {"name": "film", "parent": "1"}, "title" : "Star Wars: Episode II - Attack of the Clones", "year":"2002" , "genre":["Action", "Adventure", "Sci-Fi", "IMAX"] }
{ "create" : { "_index" : "series", "_id" : "33493", "routing" : 1} }
{ "id": "33493", "film_to_franchise": {"name": "film", "parent": "1"}, "title" : "Star Wars: Episode III - Revenge of the Sith", "year":"2005" , "genre":["Action", "Adventure", "Sci-Fi"] }
{ "create" : { "_index" : "series", "_id" : "122886", "routing" : 1} }
{ "id": "122886", "film_to_franchise": {"name": "film", "parent": "1"}, "title" : "Star Wars: Episode VII - The Force Awakens", "year":"2015" , "genre":["Action", "Adventure", "Fantasy", "Sci-Fi", "IMAX"] }

• The first entry establishes the parent: {film_to_franchise: {"name":"franchise"}}

{ "create" : { "_index" : "series", "_id" : "1", "routing" : 1} }
{ "id": "1", "film_to_franchise": {"name": "franchise"}, "title" : "Star Wars" }

• The remaining entries establish the children

{ "create" : { "_index" : "series", "_id" : "260", "routing" : 1} }
{ "id": "260", "film_to_franchise": {"name": "film", "parent": "1"}, "title" : "Star Wars: Episode IV - A New Hope", "year":"1977" , "genre":["Action", "Adventure", "Sci-Fi"] }

Parent-child search

• franchise is the parent, film is the child

# Find films (child) by franchise (parent)
curl -X GET "localhost:9200/series/_search?pretty" \
  -H "Content-Type: application/json" \
  -d  '
      {
        "query": {
          "has_parent": {
            "parent_type": "franchise",
            "query": {
              "match": {
                "title": "Star Wars"
              }
            }
          }
        }
      }
      '

## Find franchise (parent) by the film (child)!
curl -X GET "localhost:9200/series/_search?pretty" \
  -H "Content-Type: application/json" \
  -d  '
      {
        "query": {
          "has_child": {
            "type": "film",
            "query": {
              "match": {
                "title": "The Force Awakens"
              }
            }
          }
        }
      }
      '