ElasticSearch APIs

POST _reindex?slices=5&refresh
{
  "source": {
    "index": "twitter"
  },
  "dest": {
    "index": "new_twitter"
  }
}

// 其中1是特定雇员的ID，ElasticSearch中的每个文档有默认属性_id，这里是使_id=1
PUT /megacorp/employee/1
{
    "first_name" : "John",
    "last_name" :  "Smith",
    "age" :        25,
    "about" :      "I love to go rock climbing",
    "interElasticSearchts": [ "sports", "music" ]
}
PUT /megacorp/employee/2
{
    "first_name" :  "Jane",
    "last_name" :   "Smith",
    "age" :         32,
    "about" :       "I like to collect rock albums",
    "interElasticSearchts":  [ "music" ]
}
PUT /megacorp/employee/3
{
    "first_name" :  "Douglas",
    "last_name" :   "Fir",
    "age" :         35,
    "about":        "I like to build cabinets",
    "interElasticSearchts":  [ "forElasticSearchtry" ]
}

{
  "_index" :   "megacorp", // 索引名称 
  "_type" :    "employee", // 索引类型
  "_id" :      "1",        // 文档ID
  "_version" : 1,          // 版本信息
  "found" :    true,
  "_source" :  {           // 查找结果的原始JSON文档
      "first_name" :  "John",
      "last_name" :   "Smith",
      "age" :         25,
      "about" :       "I love to go rock climbing",
      "interElasticSearchts":  [ "sports", "music" ]
  }
}

{
   "took":      6,     // 花费时间，单位毫秒
   "timed_out": false,
   "_shards": { ... }, // 分片信息
   "hits": {           // 查询结果
      "total":      3, // 总共命中3个文档
      "max_score":  1, // 最大得分
      "hits": [        // 所有命中的文档JSON，默认只显示前10个
         {
            "_index":         "megacorp",
            "_type":          "employee",
            "_id":            "3",
            "_score":         1,
            "_source": {
               "first_name":  "Douglas",
               "last_name":   "Fir",
               "age":         35,
               "about":       "I like to build cabinets",
               "interests": [ "forElasticSearchtry" ]
            }
         },
         {
            "_index":         "megacorp",
            "_type":          "employee",
            "_id":            "1",
            "_score":         1,
            "_source": {
               "first_name":  "John",
               "last_name":   "Smith",
               "age":         25,
               "about":       "I love to go rock climbing",
               "interests": [ "sports", "music" ]
            }
         },
         {
            "_index":         "megacorp",
            "_type":          "employee",
            "_id":            "2",
            "_score":         1,
            "_source": {
               "first_name":  "Jane",
               "last_name":   "Smith",
               "age":         32,
               "about":       "I like to collect rock albums",
               "interests": [ "music" ]
            }
         }
      ]
   }
}

{
   ...
   "hits": {
      "total":      2,
      "max_score":  0.30685282,
      "hits": [
         {
            ...
            "_source": {
               "first_name":  "John",
               "last_name":   "Smith",
               "age":         25,
               "about":       "I love to go rock climbing",
               "interests": [ "sports", "music" ]
            }
         },
         {
            ...
            "_source": {
               "first_name":  "Jane",
               "last_name":   "Smith",
               "age":         32,
               "about":       "I like to collect rock albums",
               "interests": [ "music" ]
            }
         }
      ]
   }
}

GET /megacorp/employee/_search
{
    "query" : {
        "match" : { // match 查询，查询类型之一
            "last_name" : "Smith"
        }
    }
}

GET hsyk_diseases_info/_search
{
  "query": {
    "bool":{
      "must": [
        { "term":{ "PROVINCE.keyword": "辽宁省" } }
      ], 
      "should": [
        { "term":{ "CITY.keyword": "大连市" } },
        { "term":{ "CITY.keyword": "沈阳市" } }
      ],
      "filter": [
        
      ],
      "minimum_should_match" : 1
    }
  },
  "aggs" : {
      "group_by_district" : {
          "terms" : {
              "field":"DISTRICT.keyword"
          }
      }
    }
}

GET hsyk_diseases_info/_search
{
  "query": {
    "bool": {
      "filter": [
        {
          "bool": {
            "should": [
              { "term":
                {"PROVINCE.keyword": "辽宁省"}
              }
            ]
          }
        },
        {
          "bool": {
            "should": [
              { "terms":
                { "CITY.keyword": ["沈阳市", "大连市"]}
              }
            ]
          }
        }
      ]
    }
  },
  "aggs": {
      "group_by_district": {
          "terms": {
              "field": "DISTRICT.keyword"
          }
      }
    }
}

GET /secisland/_search
{
  "query": { // 用关键字 query 指明下面的查询子句用于 query context
    "bool": { // bool 和下面的两个 match 子句都属于 query context，用于说明文档有多匹配
      "must": [
        { "match": { "title":   "Search"        }}, 
        { "match": { "content": "Elasticsearch" }}  
      ],
      "filter": [ // 用关键字 filter 指明下面的查询子句用于 filter context，不影响 query 计算文档的 _score
        { "term":  { "status": "published" }}, // term 和 range 子句属于 filter context
        { "range": { "publish_date": { "gte": "2015-01-01" }}} // 他们会将不匹配的文档过滤掉
      ]
    }
  }
}

// 为字段配置单独的分词器
PUT my_index
{
  "mappings": {
    "_doc": {
      "properties": {
        "title": {
          "type": "text",
          // 在索引阶段，text类型的字段如果没有指定analyser，它会在
          // index settings中查找名为`default`分词器，如果没找到
          // 则默认使用`standard`分词器
          "analyzer": "standard"
        }
      }
    }
  }
}
// 为index设置全局的分词器
PUT my_index
{
    "settings": {
        "analysis": {
            "analyzer": {
                "default": {
                    "type": "ik_max_word"
                }
            }
        }
    }
}
// 与上面的等价
PUT my_index
{
  "settings": {
        "index.analysis.analyzer.default.type": "ik_max_word"
    }
}

// 添加一条数据
PUT /my_index/_doc/1
{
  "title": "brown fox"
}
// operator 默认是 or，
// `blue fox`会被 analyser 分词成为`blue`和`fox`，
// `brown fox`会被 analyser 分词为`brown`和`fox`
// 其中`fox`可以匹配上，因此是可以匹配到`brown fox`的
GET my_index/_search
{
    "query": {
        "match" : {
            "title": {
              "query": "blue fox"
              // operator 默认为 or
            }
        }
    }
}
// 上面的查询和下面的查询等价
GET /my_index/_search
{
    "query": {
        "bool": {
            "should": [
              { "term": { "title": "brown" }},
              { "term": { "title": "fox"   }}
            ]
        }
    }
}
// 下面把`operator`变成`and`，因为`blue`没有正确的匹配到结果，
// `false and true => false`因此这个查询匹配不到`brown fox`
GET /my_index/_search
{
    "query": {
        "match" : {
            "title": {
              "query": "blue fox",
              "operator": "and"
            }
        }
    }
}
// 上面的查询和下面的查询等价
GET /my_index/_search
{
    "query": {
        "bool": {
            "must": [
              { "term": { "title": "brown" }},
              { "term": { "title": "fox"   }}
            ]
        }
    }
}

// 如果加上 minimum_should_match，它会直接传入到 bool 查询中，详细的介绍可以参考
GET /my_index/_search
{
    "query": {
        "match": {
            "title": {
                "query": "quick brown fox",
                // 3 * 75% 向下取整 = 2
                "minimum_should_match": "75%"
            }
        }
    }
}
// 上面的查询和下面的查询等价
GET /my_index/_search
{
    "query": {
        "bool": {
            "should": [
                { "term": { "title": "brown" }},
                { "term": { "title": "fox"   }},
                { "term": { "title": "quick" }}
            ],
            "minimum_should_match": 2 
        }
    }
}