elasticsearch search results with sub query - elasticsearch

Question

Getting started with elasticsearch, not sure if this is possible with one query along with pagination. I have a index with two types: user & blog. Example mapping:
"mappings": {
"user": {
"properties": {
"name" : { "type": "string" }
}
},
"blog": {
"properties": {
"title" : { "type": "string" },
"author_name" : { "type": "string" }
}
}
}
}
sample data
user:
[
{"name": "jemmy"},
{"name": "Tom"}
]
blog:
[
{"title": "foo bar", "author": "jemmy"},
{"title": "magic foo", "author": "Tom"},
{"title": "bigdata for dummies", "author": "Tom"},
{"title": "elasticsearch", "author": "Tom"},
{"title": "JS cookbook", "author": "jemmy"},
]
I'd like to query on the index such a way that when I search for blog it should do subquery on on each match. For example:
POST /test_index/blog/_search
{
"query": {
"match": {
"_all": "foo"
}
}
}
Expected (pseudo) results:
[
{
title: "foo bar",
author_name: "Jemmy",
author_post_count: 2
},
{
title: "magic foo",
author_name: "Tom",
author_post_count: 3
}
]
Here author_post_count is blog post count that the user has authored. If it could return those blog posts instead of count that would be great too. Is this possible? Perhaps the term i'm using not right, but I hope my question is clear.

Answer 1

Try something like this:
POST /test_index/blog/_search
{
"query": {
"match": {
"_all": "foo"
}
},
"aggs": {
"counting_posts": {
"global": {},
"aggs": {
"authors": {
"terms": {
"field": "author",
"size": 10
}
}
}
}
}
}
Be careful though with terms aggregation because it is considering the actual tokenized list of terms from the index, not what you actually index (lowercase/uppercase, tokenized in a way or another).