elasticsearch：统计search_type=count过时，用"size":0替换

最近需要做个大数据统计看板，需要用到数据统计功能，于是用es写了个统计脚本（我都是在Kibana写好再转为C#代码），如下：

GET /m_es_name/_search?search_type=count
{
  "query": {
    "match_all": {}
  },
  "aggs": {
    "group_by_sex": {
        "terms": {
          "field": "Sex"
        }
    }
  }
}

简单的代码，但是，却报错了....错误如下

{
  "error": {
    "root_cause": [
      {
        "type": "illegal_argument_exception",
        "reason": "No search type for [count]"
      }
    ],
    "type": "illegal_argument_exception",
    "reason": "No search type for [count]"
  },
  "status": 400
}

原来，我所用的es版本中search_type=count已经被移除，不能使用，替代方案直接用"size": 0即可，改为：

GET /m_es_name/_search
{
  "size": 0,
  "query": {
    "match_all": {}
  },
  "aggs": {
    "group_by_sex": {
        "terms": {
          "field": "Sex"
        }
    }
  }
}

---

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---

文末福利：示例代码：aggs的terms及range统计方式，nested嵌套关联查询

GET /m_itlao5_com/_search
{
  "_source": false,
  "size": 0, 
  "query": {
    "bool": {
      "must": [
        {"term": {"State": "2"}},
        {
          "nested": {
            "path": "Taskinfo",
            "query": {
              "bool": {
                "must": [
                  { "term": { "Taskinfo.Stage": "100" } },
                  { "term": { "Taskinfo.Result": "2" } }
                ]
              }
            }
          }
        }
      ]
    }
  },
  "aggs": {
    "group_by_sex": {
        "terms": {
          "field": "Sex"
        }
    }
  }
}

GET /m_itlao5_com/_search
{
  "_source": false,
  "size": 0, 
  "query": {
    "bool": {
      "must": [
        {"term": {"State": "2"}},
        {
          "nested": {
            "path": "Taskinfo",
            "query": {
              "bool": {
                "must": [
                  { "term": { "Taskinfo.Stage": "100" } },
                  { "term": { "Taskinfo.Result": "2" } }
                ]
              }
            }
          }
        }
      ]
    }
  },
  "aggs": {
    "group_by_age": {
        "range": {
          "field": "Age",
          "ranges": [
              { "from": 26,  "to": 35 },
              { "from": 36, "to": 45 },
              { "from": 45, "to": 60 },
              { "from": 60 }
          ]
        }
    }
  }
}

上面老五给出两条统计语句，用于根据性别及年龄段统计，分别用到了aggs的terms及range两种统计方式，还用到了nested嵌套关联查询，这里老五不多说了，后面有时间再写