关于elasticsearch:熬夜爆肝整理的一份elasticsearch中文文档手册

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es 概括

Elaticsearch，简称为 ES，ES 是一个开源的高扩大的分布式全文搜索引擎，Elasticsearch 是面向文档型数据库，一条数据在这里就是一个文档。

基本要素

ES 是一个文档型数据库，在与传统的关系型数据库上，存在着肯定的差别。上面将 ES 外面波及到的元素与关系型数据库进行一一对应。

ElasticSearch 索引(index) 类型(type) 文档(document) 字段(field)
MySQL 数据库(database) 数据表(table) 数据行(row) 数据列(column)

索引操作

创立索引

向 ES 服务器发 PUT 申请：http://127.0.0.1:9200/shopping。创立索引只能应用 PUT 申请，PUT 是幂等性的，也就是说不存在的时候就会创立，存在的时候就不会从新创立而是返回索引曾经存在的信息。

{
    "acknowledged": true,// 响应后果
    "shards_acknowledged": true,// 分片后果
    "index": "shopping"// 索引名称
}

查问索引

向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping。

{
    "shopping": {// 索引名
        "aliases": {},// 别名
        "mappings": {},// 映射
        "settings": {// 设置
            "index": {// 设置 - 索引
                "creation_date": "1617861426847",// 设置 - 索引 - 创立工夫
                "number_of_shards": "1",// 设置 - 索引 - 主分片数量
                "number_of_replicas": "1",// 设置 - 索引 - 主分片数量
                "uuid": "J0WlEhh4R7aDrfIc3AkwWQ",// 设置 - 索引 - 主分片数量
                "version": {// 设置 - 索引 - 主分片数量
                    "created": "7080099"
                },
                "provided_name": "shopping"// 设置 - 索引 - 主分片数量
            }
        }
    }
}

查看所有索引

向 ES 服务器发 GET 申请：http://127.0.0.1:9200/_cat/indices?v。

这里申请门路中的_cat 示意查看的意思，indices 示意索引，所以整体含意就是查看以后 ES 服务器中的所有索引，就如同 MySQL 中的 show tables 的感觉，服务器响应后果如下 :

health status index    uuid                   pri rep docs.count docs.deleted store.size pri.store.size
yellow open   shopping J0WlEhh4R7aDrfIc3AkwWQ   1   1          0            0       208b           208b

删除索引

向 ES 服务器发 DELETE 申请：http://127.0.0.1:9200/shopping。

返回后果如下：

{"acknowledged": true}

文档操作

文档创立

假如索引曾经创立好了，接下来咱们来创立文档，并增加数据。这里的文档能够类比为关系型数据库中的表数据，增加的数据格式为 JSON 格局

在 Postman 中，向 ES 服务器发 POST 申请：http://127.0.0.1:9200/shopping/_doc，申请体 JSON 内容为：

{
    "title":"小米手机",
    "category":"小米",
    "images":"http://www.gulixueyuan.com/xm.jpg",
    "price":3999.00
}

返回后果

{
    "_index": "shopping",// 索引
    "_type": "_doc",// 类型 - 文档
    "_id": "ANQqsHgBaKNfVnMbhZYU",// 惟一标识，能够类比为 MySQL 中的主键，随机生成
    "_version": 1,// 版本
    "result": "created",// 后果，这里的 create 示意创立胜利
    "_shards": {//
        "total": 2,// 分片 - 总数
        "successful": 1,// 分片 - 总数
        "failed": 0// 分片 - 总数
    },
    "_seq_no": 0,
    "_primary_term": 1
}

留神，此处发送文档创立申请的形式必须为 POST，不能是 PUT，否则会产生谬误。

下面的数据创立后，因为没有指定数据唯一性标识（ID），默认状况下，ES 服务器会随机生成一个。

如果想要自定义唯一性标识，须要在创立时指定：http://127.0.0.1:9200/shopping/_doc/1，申请体 JSON 内容为：

{
    "title":"小米手机",
    "category":"小米",
    "images":"http://www.gulixueyuan.com/xm.jpg",
    "price":3999.00
}

返回后果如下：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1",//<----- 自定义唯一性标识
    "_version": 1,
    "result": "created",
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 1,
    "_primary_term": 1
}

文档查问

查看文档时，须要指明文档的唯一性标识，相似于 MySQL 中数据的主键查问
在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_doc/1。

返回后果如下：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1",
    "_version": 1,
    "_seq_no": 1,
    "_primary_term": 1,
    "found": true,
    "_source": {
        "title": "小米手机",
        "category": "小米",
        "images": "http://www.gulixueyuan.com/xm.jpg",
        "price": 3999
    }
}

查找不存在的内容，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shoppin…。返回后果如下：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1001",
    "found": false
}

查看索引下所有数据，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search。

返回后果如下：

{
    "took": 133,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 2,
            "relation": "eq"
        },
        "max_score": 1,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "1",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            }
        ]
    }
}

文档删除

删除一个文档不会立刻从磁盘上移除，它只是被标记成已删除（逻辑删除）。

在 Postman 中，向 ES 服务器发 DELETE 申请：http://127.0.0.1:9200/shopping/_doc/1
返回后果：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1",
    "_version": 4,
    "result": "deleted",//<--- 删除胜利
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 4,
    "_primary_term": 1
}

文档批改

全量批改

和新增文档一样，输出雷同的 URL 地址申请，如果申请体变动，会将原有的数据内容笼罩

在 Postman 中，向 ES 服务器发 POST 申请：http://127.0.0.1:9200/shopping/_doc/1
申请体 JSON 内容为:

{
    "title":"华为手机",
    "category":"华为",
    "images":"http://www.gulixueyuan.com/hw.jpg",
    "price":1999.00
}

批改胜利后，服务器响应后果：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1",
    "_version": 2,
    "result": "updated",//<---updated 示意数据被更新
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 2,
    "_primary_term": 1
}

部分更新

批改数据时，也能够只批改某一给条数据的部分信息

在 Postman 中，向 ES 服务器发 POST 申请：http://127.0.0.1:9200/shopping/_update/1。

申请体 JSON 内容为:

{
    "doc": {
        "title":"小米手机",
        "category":"小米"
    }
}

返回后果如下：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1",
    "_version": 3,
    "result": "updated",//<----updated 示意数据被更新
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 3,
    "_primary_term": 1
}

URL 待条件查问

查找 category 为小米的文档，在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search?q=category: 小米，返回后果如下：

{
    "took": 94,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 3,
            "relation": "eq"
        },
        "max_score": 1.3862942,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            ......
        ]
    }
}

上述为 URL 带参数模式查问，这很容易让不善者心怀歹意，或者参数值呈现中文会呈现乱码状况。为了防止这些状况，咱们可用应用带 JSON 申请体申请进行查问。

申请体带参查问

接下带 JSON 申请体，还是查找 category 为小米的文档，在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下：

{
    "query":{
        "match":{"category":"小米"}
    }
}

返回后果如下：

{
    "took": 3,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 3,
            "relation": "eq"
        },
        "max_score": 1.3862942,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            ......
        ]
    }
}

带申请体形式的查找所有内容

查找所有文档内容，也能够这样，在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下

{
    "query":{"match_all":{}
    }
}

则返回所有文档内容：

{
    "took": 2,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": 1,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            ......
        ]
    }
}

查问指定字段

如果你想查问指定字段，在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下：

{
    "query":{"match_all":{}
    },
    "_source":["title"]
}

返回后果如下：

{
    "took": 5,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": 1,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1,
                "_source": {"title": "小米手机"}
            },
            ......
        ]
    }
}

分页查问

在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下：

{
    "query":{"match_all":{}
    },
    "from":0,
    "size":2
}

返回后果如下：

{
    "took": 1,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": 1,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
        ]
    }
}

查问排序

如果你想通过排序查出价格最高的手机，在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下：

{
    "query":{"match_all":{}
    },
    "sort":{
        "price":{"order":"desc"}
    }
}

返回后果如下：

{
    "took": 96,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": null,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": null,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                },
                "sort": [3999]
            },
            ......
        ]
    }
}

多条件查问

假如想找出小米牌子，价格为 3999 元的。（must 相当于数据库的 &&）, 在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下：

{
    "query":{
        "bool":{
            "must":[{
                "match":{"category":"小米"}
            },{
                "match":{"price":3999.00}
            }]
        }
    }
}

返回后果如下：

{
    "took": 134,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 1,
            "relation": "eq"
        },
        "max_score": 2.3862944,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 2.3862944,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            }
        ]
    }
}

假如想找出小米和华为的牌子。（should 相当于数据库的 ||）在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下：

{
    "query":{
        "bool":{
            "should":[{
                "match":{"category":"小米"}
            },{
                "match":{"category":"华为"}
            }]
        },
        "filter":{
            "range":{
                "price":{"gt":2000}
            }
        }
    }
}

返回后果如下：

{
    "took": 8,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": 1.3862942,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            .....
        ]
    }
}

范畴查问

假如想找出小米和华为的牌子，价格大于 2000 元的手机。在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下：

{
    "query":{
        "bool":{
            "should":[{
                "match":{"category":"小米"}
            },{
                "match":{"category":"华为"}
            }],
            "filter":{
                "range":{
                    "price":{"gt":2000}
                }
            }
        }
    }
}

返回后果如下：

{
    "took": 72,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 1,
            "relation": "eq"
        },
        "max_score": 1.3862942,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            }
        ]
    }
}

全文检索

这性能像搜索引擎那样，如品牌输出“小华”，返回后果带回品牌有“小米”和华为的。在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下：

{
    "query":{
        "match":{"category" : "小华"}
    }
}

返回后果如下：

{
    "took": 7,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": 0.6931471,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 0.6931471,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            ......
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BtR6sHgBaKNfVnMbX5Y5",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            ......
        ]
    }
}

齐全匹配

在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下：

{
    "query":{
        "match_phrase":{"category" : "为"}
    }
}

返回后果如下：

{
    "took": 2,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 3,
            "relation": "eq"
        },
        "max_score": 0.6931471,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BtR6sHgBaKNfVnMbX5Y5",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            ......
        ]
    }
}

高亮查问

在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下：

{
    "query":{
        "match_phrase":{"category" : "为"}
    },
    "highlight":{
        "fields":{"category":{}//<---- 高亮这字段
        }
    }
}

返回后果如下：

{
    "took": 100,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 3,
            "relation": "eq"
        },
        "max_score": 0.6931471,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BtR6sHgBaKNfVnMbX5Y5",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                },
                "highlight": {
                    "category": ["华 <em> 为 </em>"//<------ 高亮一个为字。]
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "B9R6sHgBaKNfVnMbZpZ6",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                },
                "highlight": {
                    "category": ["华 <em> 为 </em>"]
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "CdR7sHgBaKNfVnMbsJb9",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                },
                "highlight": {
                    "category": ["华 <em> 为 </em>"]
                }
            }
        ]
    }
}

分组查问

在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下：

{
    "aggs":{// 聚合操作
        "price_group":{// 名称，随便起名
            "terms":{// 分组
                "field":"price"// 分组字段
            }
        }
    }
}

返回后果如下：

{
    "took": 63,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": 1,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "A9R5sHgBaKNfVnMb25Ya",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BNR5sHgBaKNfVnMb7pal",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BtR6sHgBaKNfVnMbX5Y5",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "B9R6sHgBaKNfVnMbZpZ6",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "CdR7sHgBaKNfVnMbsJb9",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            }
        ]
    },
    "aggregations": {
        "price_group": {
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [
                {
                    "key": 1999,
                    "doc_count": 5
                },
                {
                    "key": 3999,
                    "doc_count": 1
                }
            ]
        }
    }
}

下面返回后果会附带原始数据的。若不想要不附带原始数据的后果，在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下：

{
    "aggs":{
        "price_group":{
            "terms":{"field":"price"}
        }
    },
    "size":0
}

返回后果如下：

{
    "took": 60,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": null,
        "hits": []},
    "aggregations": {
        "price_group": {
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [
                {
                    "key": 1999,
                    "doc_count": 5
                },
                {
                    "key": 3999,
                    "doc_count": 1
                }
            ]
        }
    }
}

查问平均值

在 Postman 中，向 ES 服务器发 GET 申请：http://127.0.0.1:9200/shopping/_search，附带 JSON 体如下：

{
    "aggs":{
        "price_avg":{// 名称，随便起名
            "avg":{// 求均匀
                "field":"price"
            }
        }
    },
    "size":0
}

返回后果如下：

{
    "took": 14,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": null,
        "hits": []},
    "aggregations": {
        "price_avg": {"value": 2332.3333333333335}
    }
}

映射关系

有了索引库，等于有了数据库中的 database。接下来就须要建索引库 (index) 中的映射了，相似于数据库 (database) 中的表构造 (table)。创立数据库表须要设置字段名称，类型，长度，束缚等；索引库也一样，须要晓得这个类型下有哪些字段，每个字段有哪些束缚信息，这就叫做映射(mapping)。
先创立一个索引：

# PUT http://127.0.0.1:9200/user

返回后果：

{
    "acknowledged": true,
    "shards_acknowledged": true,
    "index": "user"
}

创立映射

# PUT http://127.0.0.1:9200/user/_mapping

{
    "properties": {
        "name":{
            "type": "text",
            "index": true
        },
        "sex":{
            "type": "keyword",
            "index": true
        },
        "tel":{
            "type": "keyword",
            "index": false
        }
    }
}

返回后果如下：

{"acknowledged": true}

查问映射

#GET http://127.0.0.1:9200/user/_mapping

返回后果如下：

{
    "user": {
        "mappings": {
            "properties": {
                "name": {"type": "text"},
                "sex": {"type": "keyword"},
                "tel": {
                    "type": "keyword",
                    "index": false
                }
            }
        }
    }
}

减少数据

#PUT http://127.0.0.1:9200/user/_create/1001
{
    "name":"小米",
    "sex":"男的",
    "tel":"1111"
}

返回后果如下：

{
    "_index": "user",
    "_type": "_doc",
    "_id": "1001",
    "_version": 1,
    "result": "created",
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 0,
    "_primary_term": 1
}

查找 name 含有”小“数据：

#GET http://127.0.0.1:9200/user/_search
{
    "query":{
        "match":{"name":"小"}
    }
}

返回后果如下：

{
    "took": 495,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 1,
            "relation": "eq"
        },
        "max_score": 0.2876821,
        "hits": [
            {
                "_index": "user",
                "_type": "_doc",
                "_id": "1001",
                "_score": 0.2876821,
                "_source": {
                    "name": "小米",
                    "sex": "男的",
                    "tel": "1111"
                }
            }
        ]
    }
}

查找 sex 含有”男“数据：

#GET http://127.0.0.1:9200/user/_search
{
    "query":{
        "match":{"sex":"男"}
    }
}

返回后果如下：

{
    "took": 1,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 0,
            "relation": "eq"
        },
        "max_score": null,
        "hits": []}
}

找不想要的后果，只因创立映射时 ”sex” 的类型为 ”keyword”。”sex” 只能齐全为”男的“，能力得出原数据。

#GET http://127.0.0.1:9200/user/_search
{
    "query":{
        "match":{"sex":"男的"}
    }
}

返回后果如下：

{
    "took": 2,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 1,
            "relation": "eq"
        },
        "max_score": 0.2876821,
        "hits": [
            {
                "_index": "user",
                "_type": "_doc",
                "_id": "1001",
                "_score": 0.2876821,
                "_source": {
                    "name": "小米",
                    "sex": "男的",
                    "tel": "1111"
                }
            }
        ]
    }
}

查询电话

# GET http://127.0.0.1:9200/user/_search
{
    "query":{
        "match":{"tel":"11"}
    }
}

返回后果如下：

{
    "error": {
        "root_cause": [
            {
                "type": "query_shard_exception",
                "reason": "failed to create query: Cannot search on field [tel] since it is not indexed.",
                "index_uuid": "ivLnMfQKROS7Skb2MTFOew",
                "index": "user"
            }
        ],
        "type": "search_phase_execution_exception",
        "reason": "all shards failed",
        "phase": "query",
        "grouped": true,
        "failed_shards": [
            {
                "shard": 0,
                "index": "user",
                "node": "4P7dIRfXSbezE5JTiuylew",
                "reason": {
                    "type": "query_shard_exception",
                    "reason": "failed to create query: Cannot search on field [tel] since it is not indexed.",
                    "index_uuid": "ivLnMfQKROS7Skb2MTFOew",
                    "index": "user",
                    "caused_by": {
                        "type": "illegal_argument_exception",
                        "reason": "Cannot search on field [tel] since it is not indexed."
                    }
                }
            }
        ]
    },
    "status": 400
}

报错只因创立映射时 ”tel” 的 ”index” 为 false。

正文完
elasticsearch
发表至： elasticsearch
2022-07-02
 0
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