倒排索引
正排索引(传统)
id content
1001 my name is zhang san
1002 my name is li si
倒排索引
keyword id
name 1001, 1002
zhang 1001
Elasticsearch 是面向文档型数据库,一条数据在这里就是一个文档。 为了方便大家理解,我们将 Elasticsearch 里存储文档数据和关系型数据库 MySQL 存储数据的概念进行一个类比
ES 里的 Index 可以看做一个库,而 Types 相当于表, Documents 则相当于表的行。这里 Types 的概念已经被逐渐弱化, Elasticsearch 6.X 中,一个 index 下已经只能包含一个type, Elasticsearch 7.X 中, Type 的概念已经被删除了。
对比关系型数据库,创建索引就等同于创建数据库。
在 Postman 中,向 ES 服务器发 PUT 请求 : http://127.0.0.1:9200/shopping
请求后,服务器返回响应:
{ "acknowledged": true,//响应结果 "shards_acknowledged": true,//分片结果 "index": "shopping"//索引名称 }
后台日志:
[2021-04-08T13:57:06,954][INFO ][o.e.c.m.MetadataCreateIndexService] [DESKTOP-LNJQ0VF] [shopping] creating index, cause [api], templates [], shards [1]/[1], mappings []
如果重复发 PUT 请求 : http://127.0.0.1:9200/shopping 添加索引,会返回错误信息 :
{ "error": { "root_cause": [ { "type": "resource_already_exists_exception", "reason": "index [shopping/J0WlEhh4R7aDrfIc3AkwWQ] already exists", "index_uuid": "J0WlEhh4R7aDrfIc3AkwWQ", "index": "shopping" } ], "type": "resource_already_exists_exception", "reason": "index [shopping/J0WlEhh4R7aDrfIc3AkwWQ] already exists", "index_uuid": "J0WlEhh4R7aDrfIc3AkwWQ", "index": "shopping" }, "status": 400 }
索引-查询 & 删除
查看所有索引
在 Postman 中,向 ES 服务器发 GET 请求 : http://127.0.0.1:9200/_cat/indices?v
这里请求路径中的_cat 表示查看的意思, indices 表示索引,所以整体含义就是查看当前 ES服务器中的所有索引,就好像 MySQL 中的 show tables 的感觉,服务器响应结果如下 :
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
表头 含义
health 当前服务器健康状态: green(集群完整) yellow(单点正常、集群不完整) red(单点不正常)
status 索引打开、关闭状态
index 索引名
uuid 索引统一编号
pri 主分片数量
rep 副本数量
docs.count 可用文档数量
docs.deleted 文档删除状态(逻辑删除)
store.size 主分片和副分片整体占空间大小
pri.store.size 主分片占空间大小
在 Postman 中,向 ES 服务器发 GET 请求 : http://127.0.0.1:9200/shopping
返回结果如下:
{ "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 - 创建时间 "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 } } } }
在 Postman 中,向 ES 服务器发 DELETE 请求 : http://127.0.0.1:9200/shopping
返回结果如下:
{ "acknowledged": true }
再次查看所有索引,GET http://127.0.0.1:9200/_cat/indices?v 返回结果如下:
health status index uuid pri rep docs.count docs.deleted store.size pri.store.size
成功删除。
文档-创建(Put & Post)
假设索引已经创建好了,接下来我们来创建文档,并添加数据。这里的文档可以类比为关系型数据库中的表数据,添加的数据格式为 JSON 格式
在 Postman 中,向 ES 服务器发 POST 请求 : http://127.0.0.1:9200/shopping/_doc,请求体JSON内容为:
{ "title":"小米手机", "category":"小米", "images":"http://www.gulixueyuan.com/xm.jpg", "price":3999.00 }
注意,此处发送请求的方式必须为 POST,不能是 PUT,否则会发生错误 。
返回结果:
{ "_index": "shopping",//索引 "_type": "_doc",//类型-文档 "_id": "ANQqsHgBaKNfVnMbhZYU",//唯一标识,可以类比为 MySQL 中的主键,随机生成 "_version": 1,//版本 "result": "created",//结果,这里的 create 表示创建成功 "_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 }
上面的数据创建后,由于没有指定数据唯一性标识(ID),默认情况下, ES 服务器会随机生成一个。
如果想要自定义唯一性标识,需要在创建时指定: http://127.0.0.1:9200/shopping/_doc/1,请求体JSON内容为:
{ "title":"小米手机", "category":"小米", "images":"http://www.gulixueyuan.com/xm.jpg", "price":3999.00 }
返回结果如下:
{ "_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 }
查看文档时,需要指明文档的唯一性标识,类似于 MySQL 中数据的主键查询
在 Postman 中,向 ES 服务器发 GET 请求 : http://127.0.0.1:9200/shopping/_doc/1 。
返回结果如下:
{ "_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 请求 : http://127.0.0.1:9200/shopping/_doc/1001。
返回结果如下:
{ "_index": "shopping", "_type": "_doc", "_id": "1001", "found": false }
查看索引下所有数据,向 ES 服务器发 GET 请求 : http://127.0.0.1:9200/shopping/_search。
返回结果如下:
{ "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 } } ] } }
全量修改 & 局部修改 & 删除
全量修改
和新增文档一样,输入相同的 URL 地址请求,如果请求体变化,会将原有的数据内容覆盖
在 Postman 中,向 ES 服务器发 POST 请求 : http://127.0.0.1:9200/shopping/_doc/1
请求体JSON内容为:
{ "title":"华为手机", "category":"华为", "images":"http://www.gulixueyuan.com/hw.jpg", "price":1999.00 }
修改成功后,服务器响应结果:
{ "_index": "shopping", "_type": "_doc", "_id": "1", "_version": 2, "result": "updated",//<-----------updated 表示数据被更新 "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 2, "_primary_term": 1 }
修改数据时,也可以只修改某一给条数据的局部信息
在 Postman 中,向 ES 服务器发 POST 请求 : http://127.0.0.1:9200/shopping/_update/1。
请求体JSON内容为:
{ "doc": { "title":"小米手机", "category":"小米" } }
返回结果如下:
{ "_index": "shopping", "_type": "_doc", "_id": "1", "_version": 3, "result": "updated",//<-----------updated 表示数据被更新 "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 3, "_primary_term": 1 }
在 Postman 中,向 ES 服务器发 GET请求 : http://127.0.0.1:9200/shopping/_doc/1,查看修改内容:
{ "_index": "shopping", "_type": "_doc", "_id": "1", "_version": 3, "_seq_no": 3, "_primary_term": 1, "found": true, "_source": { "title": "小米手机", "category": "小米", "images": "http://www.gulixueyuan.com/hw.jpg", "price": 1999 } }
删除一个文档不会立即从磁盘上移除,它只是被标记成已删除(逻辑删除)。
在 Postman 中,向 ES 服务器发 DELETE 请求 : http://127.0.0.1:9200/shopping/_doc/1
返回结果:
{ "_index": "shopping", "_type": "_doc", "_id": "1", "_version": 4, "result": "deleted",//<---删除成功 "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 4, "_primary_term": 1 }
在 Postman 中,向 ES 服务器发 GET请求 : http://127.0.0.1:9200/shopping/_doc/1,查看是否删除成功:
{ "_index": "shopping", "_type": "_doc", "_id": "1", "found": false }
假设有以下文档内容,(在 Postman 中,向 ES 服务器发 GET请求 : http://127.0.0.1:9200/shopping/_search):
{ "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", "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 } } ] } }
查找category为小米的文档,在 Postman 中,向 ES 服务器发 GET请求 : http://127.0.0.1:9200/shopping/_search?q=category:小米,返回结果如下:
{ "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 } }, { "_index": "shopping", "_type": "_doc", "_id": "A9R5sHgBaKNfVnMb25Ya", "_score": 1.3862942, "_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": 1.3862942, "_source": { "title": "小米手机", "category": "小米", "images": "http://www.gulixueyuan.com/xm.jpg", "price": 1999 } } ] } }
上述为URL带参数形式查询,这很容易让不善者心怀恶意,或者参数值出现中文会出现乱码情况。为了避免这些情况,我们可用使用带JSON请求体请求进行查询。
请求体带参查询
接下带JSON请求体,还是查找category为小米的文档,在 Postman 中,向 ES 服务器发 GET请求 : http://127.0.0.1:9200/shopping/_search,附带JSON体如下:
{ "query":{ "match":{ "category":"小米" } } }
返回结果如下:
{ "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 } }, { "_index": "shopping", "_type": "_doc", "_id": "A9R5sHgBaKNfVnMb25Ya", "_score": 1.3862942, "_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": 1.3862942, "_source": { "title": "小米手机", "category": "小米", "images": "http://www.gulixueyuan.com/xm.jpg", "price": 1999 } } ] } }
查找所有文档内容,也可以这样,在 Postman 中,向 ES 服务器发 GET请求 : 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 } }, { "_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 } } ] } }
如果你想查询指定字段,在 Postman 中,向 ES 服务器发 GET请求 : http://127.0.0.1:9200/shopping/_search,附带JSON体如下:
{ "query":{ "match_all":{} }, "_source":["title"] }
返回结果如下:
{ "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" } }, { "_index": "shopping", "_type": "_doc", "_id": "A9R5sHgBaKNfVnMb25Ya", "_score": 1, "_source": { "title": "小米手机" } }, { "_index": "shopping", "_type": "_doc", "_id": "BNR5sHgBaKNfVnMb7pal", "_score": 1, "_source": { "title": "小米手机" } }, { "_index": "shopping", "_type": "_doc", "_id": "BtR6sHgBaKNfVnMbX5Y5", "_score": 1, "_source": { "title": "华为手机" } }, { "_index": "shopping", "_type": "_doc", "_id": "B9R6sHgBaKNfVnMbZpZ6", "_score": 1, "_source": { "title": "华为手机" } }, { "_index": "shopping", "_type": "_doc", "_id": "CdR7sHgBaKNfVnMbsJb9", "_score": 1, "_source": { "title": "华为手机" } } ] } }
在 Postman 中,向 ES 服务器发 GET请求 : http://127.0.0.1:9200/shopping/_search,附带JSON体如下:
{ "query":{ "match_all":{} }, "from":0, "size":2 }
返回结果如下:
{ "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 } }, { "_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 } } ] } }
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请求 : http://127.0.0.1:9200/shopping/_search,附带JSON体如下:
{ "query":{ "match_all":{} }, "sort":{ "price":{ "order":"desc" } } }
返回结果如下:
{ "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 ] }, { "_index": "shopping", "_type": "_doc", "_id": "A9R5sHgBaKNfVnMb25Ya", "_score": null, "_source": { "title": "小米手机", "category": "小米", "images": "http://www.gulixueyuan.com/xm.jpg", "price": 1999 }, "sort": [ 1999 ] }, { "_index": "shopping", "_type": "_doc", "_id": "BNR5sHgBaKNfVnMb7pal", "_score": null, "_source": { "title": "小米手机", "category": "小米", "images": "http://www.gulixueyuan.com/xm.jpg", "price": 1999 }, "sort": [ 1999 ] }, { "_index": "shopping", "_type": "_doc", "_id": "BtR6sHgBaKNfVnMbX5Y5", "_score": null, "_source": { "title": "华为手机", "category": "华为", "images": "http://www.gulixueyuan.com/xm.jpg", "price": 1999 }, "sort": [ 1999 ] }, { "_index": "shopping", "_type": "_doc", "_id": "B9R6sHgBaKNfVnMbZpZ6", "_score": null, "_source": { "title": "华为手机", "category": "华为", "images": "http://www.gulixueyuan.com/xm.jpg", "price": 1999 }, "sort": [ 1999 ] }, { "_index": "shopping", "_type": "_doc", "_id": "CdR7sHgBaKNfVnMbsJb9", "_score": null, "_source": { "title": "华为手机", "category": "华为", "images": "http://www.gulixueyuan.com/xm.jpg", "price": 1999 }, "sort": [ 1999 ] } ] } }
假设想找出小米牌子,价格为3999元的。(must相当于数据库的&&)
在 Postman 中,向 ES 服务器发 GET请求 : 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 } }] } } }
返回结果如下:
{ "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 } } ] } }
假设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请求 : 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 } } } } }
返回结果如下:
{ "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 } }, { "_index": "shopping", "_type": "_doc", "_id": "A9R5sHgBaKNfVnMb25Ya", "_score": 1.3862942, "_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": 1.3862942, "_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": 1.3862942, "_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": 1.3862942, "_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": 1.3862942, "_source": { "title": "华为手机", "category": "华为", "images": "http://www.gulixueyuan.com/xm.jpg", "price": 1999 } } ] } }
假设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请求 : 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 } } } } } }
返回结果如下:
{ "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 & 完全匹配 & 高亮查询
全文检索
这功能像搜索引擎那样,如品牌输入“小华”,返回结果带回品牌有“小米”和华为的。
在 Postman 中,向 ES 服务器发 GET请求 : http://127.0.0.1:9200/shopping/_search,附带JSON体如下
{ "query":{ "match":{ "category" : "小华" } } }
返回结果如下:
{ "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": "A9R5sHgBaKNfVnMb25Ya", "_score": 0.6931471, "_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": 0.6931471, "_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": 0.6931471, "_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": 0.6931471, "_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": 0.6931471, "_source": { "title": "华为手机", "category": "华为", "images": "http://www.gulixueyuan.com/xm.jpg", "price": 1999 } } ] } }
在 Postman 中,向 ES 服务器发 GET请求 : http://127.0.0.1:9200/shopping/_search,附带JSON体如下:
{ "query":{ "match_phrase":{ "category" : "为" } } }
返回结果如下:
{ "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 } }, { "_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 } }, { "_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 } } ] } }
在 Postman 中,向 ES 服务器发 GET请求 : 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 } } }
返回结果如下:
{ "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>" ] } } ] } }
聚合查询
聚合允许使用者对 es 文档进行统计分析,类似与关系型数据库中的 group by,当然还有很多其他的聚合,例如取最大值max、平均值avg等等。
接下来按price字段进行分组:
在 Postman 中,向 ES 服务器发 GET请求 : http://127.0.0.1:9200/shopping/_search,附带JSON体如下
{ "aggs":{//聚合操作 "price_group":{//名称,随意起名 "terms":{//分组 "field":"price"//分组字段 } } } }
返回结果如下:
{ "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 } ] } } }
上面返回结果会附带原始数据的。若不想要不附带原始数据的结果,在 Postman 中,向 ES 服务器发 GET请求 : http://127.0.0.1:9200/shopping/_search,附带JSON体如下
{ "aggs":{ "price_group":{ "terms":{ "field":"price" } } }, "size":0 }
返回结果如下:
{ "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 } ] } } }
若想对所有手机价格求平均值。
在 Postman 中,向 ES 服务器发 GET请求 : http://127.0.0.1:9200/shopping/_search,附带JSON体如下
{ "aggs":{ "price_avg":{//名称,随意起名 "avg":{//求平均 "field":"price" } } }, "size":0 }
返回结果如下:
{ "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。
接下来就需要建索引库(index)中的映射了,类似于数据库(database)中的表结构(table)。
创建数据库表需要设置字段名称,类型,长度,约束等;索引库也一样,需要知道这个类型下有哪些字段,每个字段有哪些约束信息,这就叫做映射(mapping)。
先创建一个索引:
# PUT http://127.0.0.1:9200/user
返回结果:
{ "acknowledged": true, "shards_acknowledged": true, "index": "user" }
创建映射
# 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 } } }
返回结果如下:
{ "acknowledged": true }
查询映射
#GET http://127.0.0.1:9200/user/_mapping
返回结果如下:
{ "user": { "mappings": { "properties": { "name": { "type": "text" }, "sex": { "type": "keyword" }, "tel": { "type": "keyword", "index": false } } } } }
增加数据
#PUT http://127.0.0.1:9200/user/_create/1001 { "name":"小米", "sex":"男的", "tel":"1111" }
返回结果如下:
{ "_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" } } }
返回结果如下:
{ "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" } } }
返回结果如下:
{ "took": 1, "timed_out": false, "_shards": { "total": 1, "successful": 1, "skipped": 0, "failed": 0 }, "hits": { "total": { "value": 0, "relation": "eq" }, "max_score": null, "hits": [] } }
找不想要的结果,只因创建映射时"sex"的类型为"keyword"。
"sex"只能完全为”男的“,才能得出原数据。
#GET http://127.0.0.1:9200/user/_search { "query":{ "match":{ "sex":"男的" } } }
返回结果如下:
{ "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" } } }
返回结果如下:
{ "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 }
报错只因创建映射时"tel"的"index"为false。