ElasticSearch41：初识搜索引擎_上机动手实战如何定制搜索结果的排序规则

1.默认排序规则

默认情况下，是按照_score降序排序的，然后在某些情况下，如filter，不计算_score，所以没有可用的_score

例子：

GET /test_index/test_type/_search

{

  "query": {

    "bool": {

      "filter": {

        "term": {

          "test_field": "hello"

        }

      }

    }

    

  }

}

执行结果：

{
"took": 33,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 0,
"max_score": null,
"hits": []
}
}

当然，还有constant_score

GET /test_index/test_type/_search

{

  "query": {

    "constant_score": {

      "filter": {

        "term": {

          "test_field": "hello"

        }

      }

    }

  }    

}

执行结果：

{
"took": 3,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 0,
"max_score": null,
"hits": []
}
}

2.定制排序规则

例子：查询10到50岁的员工，并按照join_date正序排序

GET /company/employee/_search

{

  "query": {

    "range": {

      "age": {

        "gte": 10,

        "lte": 50

      }

    }

  },

  "sort": [

    {

      "join_date": "asc"

    }

  ]

}

执行结果：

{
"took": 565,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 3,
"max_score": null,
"hits": [
{
"_index": "company",
"_type": "employee",
"_id": "1",
"_score": null,
"_source": {
"address": {
"province": "zhejiang",
"city": "wenzhou",
"country": "china"
},
"name": "tom",
"age": 31,
"join_date": "2015-01-02"
},
"sort": [
1420156800000
]
},
{
"_index": "company",
"_type": "employee",
"_id": "2",
"_score": null,
"_source": {
"address": {
"province": "zhejiang",
"city": "hangzhou",
"country": "china"
},
"name": "jerry",
"age": 25,
"join_date": "2017-01-02"
},
"sort": [
1483315200000
]
},
{
"_index": "company",
"_type": "employee",
"_id": "3",
"_score": null,
"_source": {
"address": {
"province": "zhejiang",
"city": "ningbo",
"country": "china"
},
"name": "tiny",
"age": 18,
"join_date": "2018-01-02"
},
"sort": [
1514851200000
]
}
]
}
}