ES-通過API進行數據管理(增刪改查) · ES存儲搜索引擎入門

[TOC] ## 數據管理 ES提供近乎實時的數據操縱和搜索能力。默認情況下，從索引/更新/刪除數據到在搜索結果中出現數據之前，可以預期延遲一秒鐘（刷新間隔）。這是與其他SQL數據庫的重要區別，SQL數據庫中的數據在事務完成后立即可用。 ### **添加Document： `PUT /<index>/<type>/<ID>`** 現在我們往"customer"中創建一個ID為1 的document： ``` curl -X PUT "localhost:9200/customer/_doc/1?pretty" -H 'Content-Type: application/json' -d' { "name": "John Doe" } ' ``` 運行結果如下： ```cmd { "_index" : "customer", "_type" : "_doc", "_id" : "1", "_version" : 1, "result" : "created", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "_seq_no" : 0, "_primary_term" : 1 } ``` 通過上面的命令，我們已經成功的添加了一個customer document在customer index中 >[info] 值得注意的是,Elasticsearch不需要在顯式地創建一個索引之前,我們就可以創建索引文檔。在前面的示例中,如果沒有事先已經存在索引，Elasticsearch將自動創建索引。其中，ID為可選項，假如我們沒有指定ID，ES則會自動生成一個唯一的ID，如下： ``` curl -X POST "localhost:9200/customer/_doc?pretty" -H 'Content-Type: application/json' -d' { "name": "Cherish" } ' ``` 運行結果如下： ```cmd { "_index" : "customer", "_type" : "_doc", "_id" : "EJLLSWcBMnaFSnQdDr7_", "_version" : 1, "result" : "created", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "_seq_no" : 0, "_primary_term" : 3 } ``` 注意：我們這里使用了`POST`而不是`PUT`,添加后，生成的ID為`EJLLSWcBMnaFSnQdDr7_`   ### **查詢Document： `GET /<index>/<type>/<ID>`** 查詢索引Customer中ID為1的Document命令： ``` curl -X GET "localhost:9200/customer/_doc/1?pretty" ``` 查詢結果如下： ```cmd { "_index" : "customer", "_type" : "_doc", "_id" : "1", "_version" : 1, "found" : true, "_source" : { "name" : "John Doe" } } ``` 根據查詢結果，ID為1的document中，name=“John Doe” ### **替換Document：`PUT /<index>/<type>/<ID>`** 添加Document時，假設ID已存在，如前面添加的ID為1，這將會覆蓋原來的記錄，如下： ``` curl -X PUT "localhost:9200/customer/_doc/1?pretty" -H 'Content-Type: application/json' -d' { "name": "Milton" } ' ``` 重新查詢時 `curl -X GET "localhost:9200/customer/_doc/1?pretty"` 查詢結果如下： ```cmd { "_index" : "customer", "_type" : "_doc", "_id" : "1", "_version" : 2, "found" : true, "_source" : { "name" : "Milton" } } ``` 通過上面結果可以得知，ID為1的Document已經被替換。注意“_version”已自增 ### **更新Document： `POST /<index>/<type>/<ID>/_update`** - 更新customer中ID為1的Document中的name為“Apple” ``` curl -X POST "localhost:9200/customer/_doc/1/_update?pretty" -H 'Content-Type: application/json' -d' { "doc": { "name": "Apple" } } ' ``` - 更新customer中ID為1的Document中的name為“Tom”，并且添加新的字段age ``` curl -X POST "localhost:9200/customer/_doc/1/_update?pretty" -H 'Content-Type: application/json' -d' { "doc": { "name": "Tom", "age": 20 } } ' ``` - 使用Scripts腳本更新Document中的age+5 ``` curl -X POST "localhost:9200/customer/_doc/1/_update?pretty" -H 'Content-Type: application/json' -d' { "script" : "ctx._source.age += 5" } ' ``` 上面例子中`ctx._source`代表被更新的對象本身。 ### **刪除Document： `DELETE /<index>/<type>/<ID>`** 刪除customer中ID為2的Document ``` curl -X DELETE "localhost:9200/customer/_doc/2?pretty" ``` 假設文檔不存在，則返回如下 ``` { "_index" : "customer", "_type" : "_doc", "_id" : "2", "_version" : 1, "result" : "not_found", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "_seq_no" : 0, "_primary_term" : 1 } ``` ### **批量處理：`POST <index>/<type>/_bulk`** 在ES中，除了上面針對單個Document增、刪、改、查之外，ES還提供了一個強大的API`_bulk`，它具備了批量操作的能力。 1. 批量添加兩個Document ``` curl -X POST "localhost:9200/customer/_doc/_bulk?pretty" -H 'Content-Type: application/json' -d' {"index":{"_id":"11"}} {"name": "Milton" } {"index":{"_id":"22"}} {"name": "Cherish" } ' ``` 運行結果如下： ```cmd { "took" : 272, "errors" : false, "items" : [ { "index" : { "_index" : "customer", "_type" : "_doc", "_id" : "11", "_version" : 1, "result" : "created", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "_seq_no" : 0, "_primary_term" : 3, "status" : 201 } }, { "index" : { "_index" : "customer", "_type" : "_doc", "_id" : "22", "_version" : 1, "result" : "created", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "_seq_no" : 1, "_primary_term" : 3, "status" : 201 } } ] } ``` 通過上面可知，已經新增的兩條Document 2. 批量更新和刪除Document ``` curl -X POST "localhost:9200/customer/_doc/_bulk?pretty" -H 'Content-Type: application/json' -d' {"update":{"_id":"11"}} {"doc": { "name": "Milton Love Cherish" } } {"delete":{"_id":"22"}} ' ``` 運行結果如下： ```cmd { "took" : 269, "errors" : false, "items" : [ { "update" : { "_index" : "customer", "_type" : "_doc", "_id" : "11", "_version" : 2, "result" : "updated", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "_seq_no" : 1, "_primary_term" : 3, "status" : 200 } }, { "delete" : { "_index" : "customer", "_type" : "_doc", "_id" : "22", "_version" : 2, "result" : "deleted", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "_seq_no" : 2, "_primary_term" : 3, "status" : 200 } } ] } ``` 通過上面的運行結果可知，更新與刪除都成功了。