Learning Elasticsearch

The has_parent query

We can use the has_parent to query child documents based on a query on the parent. For example, we want to find all the reviews written for a given product. The parent document is product, and the child document is product_review. The has_parent query is shown here:

#Has_Parent (Reviews for iphone) POST chapter7/product_review/_search {   "query" : {     "has_parent": {       "parent_type": "product",       "query": {         "term": {           "product_name": "iphone"         }       }     }   } }

The response will contain the product reviews for iphone. The response to the preceding query is as follows:

{   ....   "hits": {     "total": 1,     "max_score": 1,     "hits": [       {         "_index": "chapter7",         "_type": "product_review",         "_id": "AVsMFvpeF21JdiUIl1RT",         "_score": 1, "_routing": "1", ...