第一章 概述-無

第二章 開始使用

2.1 基本檢索

2.1.1 計算文檔數量

GET books/_count

2.1.2 檢索單個ID文檔

GET books/_doc/1

2.1.3 檢索多個ID文檔

GET books/_search
{
  "query": {
    "ids": {
      "values": [1,2,3]
    }
  }
}

2.1.4 檢索所有文檔

GET books/_search

2.1.5 抑制元數據: "_source": false

• 寫法1

  GET books/_search
  {
  "_source": false, 
  "query": {
    "ids": {
      "values": [1,2,3]
    }
  }
  }

• 寫法2

  GET books/_search?_source=false
  {
  "query": {
    "ids": {
      "values": [1,2,3]
    }
  }
  }

  2.1.6 多字段搜索: multi_match

  GET books/_search
  {
  "query": {
    "multi_match": {
      "query": "java",
      "fields": ["title", "author"]
    }
  }
  }

  2.1.7 提升結果分數:"title^2"

  GET books/_search
  {
  "query": {
    "multi_match": {
      "query": "java",
      "fields": ["title^2", "author"]
    }
  }
  }

  2.1.8 短語搜索: match_phrase

  2.1.9 高亮結果:highlight>fields>列名

  GET books/_search
  {
  "query": {
    "multi_match": {
      "query": "java",
      "fields": ["title^2", "author"]
    }
  },
  "highlight": {
    "fields": {
      "title": {}
    }
  }
  }

  2.1.10 詞項:term

  GET books/_search
  {
  "query": {
    "term": {
      "title.keyword": {
        "value": "Effective Java"
      }
    }
  }
  }

  2.1.11 範圍查詢:range

  GET books/_search
  {
  "query": {
    "range": {
      "amazon_rating": {
        "gte": 1.0,
        "lte": 2.0
      }
    }
  }
  }

  2.2 bool查詢(複合查詢)

  複合查詢有以下幾種:

• bool查詢->最常用
• constant_score常數分查詢
• function_score函數分查詢
• boosting查詢
• dis_max查詢(分離最大化)

bool查詢可以使用4種子句

• must
• must_not
• filter 只過濾,不參與分數計算
• should 不要求強制匹配,可以配合 minimum_should_match最少要滿足的條件數

2.3 聚合

聚合分類:

• 指標聚合:metric aggregation
• 桶聚合: bucket aggregation
• 管道聚合: pipe aggregation: 其他聚合結果進行聚合

2.3.1 指標聚合

count/sum/min/max/avg

GET books/_search
{
  "size": 0,
  "aggs": {
    "amazing_rating_stat": {
      "stats": {
        "field": "amazon_rating"
      }
    }
  }
}

result:

{
  "took": 0,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 7,
      "relation": "eq"
    },
    "max_score": null,
    "hits": []
  },
  "aggregations": {
    "amazing_rating_stat": {
      "count": 7,
      "min": 1.7000000476837158,
      "max": 4.800000190734863,
      "avg": 3.357142857142857,
      "sum": 23.5
    }
  }
}

2.3.2 bucket聚合-1-histogram

數據:

{
  "took": 1,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 7,
      "relation": "eq"
    },
    "max_score": 1,
    "hits": [
      {
        "_id": "1",
        "_source": {
          "amazon_rating": 4.7
        }
      },
      {
        "_id": "2",
        "_source": {
          "amazon_rating": 4.8
        }
      },
      {
        "_id": "3",
        "_source": {
          "amazon_rating": 4.2
        }
      },
      {
        "_id": "z4vu5ZgBKp_2wfj9FsRL",
        "_source": {
          "amazon_rating": 1.7
        }
      },
      {
        "_id": "0Ivu5ZgBKp_2wfj96cSF",
        "_source": {
          "amazon_rating": 2.7
        }
      },
      {
        "_id": "0Yvv5ZgBKp_2wfj9ysT3",
        "_source": {
          "amazon_rating": 2.7
        }
      },
      {
        "_id": "0ovw5ZgBKp_2wfj9IMQW",
        "_source": {
          "amazon_rating": 2.7
        }
      }
    ]
  }
}

聚合dsl查詢

GET books/_search
{
  "size": 0,
  "aggs": {
    "amazing_rating_histogram": {
      "histogram": {
        "field": "amazon_rating",
        "interval": 2
      }
    }
  }
}

結果:

{
  "took": 0,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 7,
      "relation": "eq"
    },
    "max_score": null,
    "hits": []
  },
  "aggregations": {
    "amazing_rating_histogram": {
      "buckets": [
        {
          "key": 0,
          "doc_count": 1
        },
        {
          "key": 2,
          "doc_count": 3
        },
        {
          "key": 4,
          "doc_count": 3
        }
      ]
    }
  }
}

2.3.3 bucket聚合-2-range bucket

GET books/_search
{
  "size": 0,
  "aggs": {
    "amazing_rating_range": {
      "range": {
        "field": "amazon_rating",
        "ranges": [
          {
            "to": 2
          },
          {
            "from": 2,
            "to": 3
          },
          {
            "from": 3,
            "to": 5
          }
        ]
      }
    }
  }
}

結果:

{
  "took": 0,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 7,
      "relation": "eq"
    },
    "max_score": null,
    "hits": []
  },
  "aggregations": {
    "amazing_rating_range": {
      "buckets": [
        {
          "key": "*-2.0",
          "to": 2,
          "doc_count": 1
        },
        {
          "key": "2.0-3.0",
          "from": 2,
          "to": 3,
          "doc_count": 3
        },
        {
          "key": "3.0-5.0",
          "from": 3,
          "to": 5,
          "doc_count": 3
        }
      ]
    }
  }
}