ElasticSearch 中 nested 類型聚合查詢語句

建索引：
PUT es_latent_buy_brands_frequency
{
  "settings": {
    "number_of_replicas": 1
    , "number_of_shards": 3
  }, 
  "mappings": {
    "doc": {
      "properties": {
        "user_id":{
          "type": "keyword"
        },
        "latent_buy_brand_frequency":{
          "type": "nested",
          "properties": {
            "name":{
              "type":"keyword"
            }
          }
        }
      }
    }
  }
}

查詢索引內數據：
POST es_latent_buy_brands_frequency/_search

查看mapping：
GET es_latent_buy_brands_frequency/_mapping

term查詢：
POST es_latent_buy_brands_frequency/_search
{
  "query": {
    "term": {
      "user_id": {
        "value": "1750119"
      }
    }
  }
}

聚合查詢：
POST es_latent_buy_brands_frequency/_search
{
  "aggs": {
    "buy_goods_brand": {
      "nested": {
        "path": "latent_buy_brand_frequency"
      },
      "aggs": {
        "agg_by_buy_goods_brand": {
          "terms": {
            "field": "latent_buy_brand_frequency.name",
            "size": 10
          }
        }
      }
    }
  }
}