Elasticsearch基础增删改查与批量操作API

た入场券 2023-06-25 04:39 7阅读 0赞

> 本文基于Elasticsearch7.x版本.

### 基础增删改查 ###

**新增文档**

(1) 语法

a. 语法一

PUT /index_name/_doc/id
    {
    	"字段名" : "字段值"
    	...
    }
    
    POST /index_name/_doc/id
    {
    	"字段名" : "字段值"
    	...
    }

如果id不存在, 则创建新文档. 如果id存在, 则覆盖旧文档, 同时版本号增加.

b. 语法二

PUT /index_name/_create/id
    {
    	"字段名" : "字段值"
    	...
    }
    
    POST /index_name/_create/id
    {
    	"字段名" : "字段值"
    	...
    }

如果id已存在, 则新增失败.

c. 语法三

POST /index_name/_doc/
    {
    	"字段名" : "字段值"
    	...
    }

不指定id, 自动生成.

(2) 实例

a. 实例一

PUT twitter/_doc/1
    {
        "user" : "kimchy",
        "post_date" : "2019-11-15T14:12:12",
        "message" : "trying out Elasticsearch"
    }

结果:

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

b. 实例二

PUT twitter/_create/1
    {
        "user" : "kimchy",
        "post_date" : "2019-11-15T14:12:12",
        "message" : "trying out Elasticsearch"
    }

结果:

{
      "error": {
        "root_cause": [
          {
            "type": "version_conflict_engine_exception",
            "reason": "[1]: version conflict, document already exists (current version [1])",
            "index_uuid": "hockYagkQH620k0lEi2HQA",
            "shard": "0",
            "index": "twitter"
          }
        ],
        "type": "version_conflict_engine_exception",
        "reason": "[1]: version conflict, document already exists (current version [1])",
        "index_uuid": "hockYagkQH620k0lEi2HQA",
        "shard": "0",
        "index": "twitter"
      },
      "status": 409
    }

c. 实例三

POST /twitter/_doc/
    {
      "user" : "kimchy",
      "post_date" : "2019-11-15T14:12:12",
      "message" : "trying out Elasticsearch"
    }

结果

{
      "_index" : "twitter",
      "_type" : "_doc",
      "_id" : "f1_fOm8Bqop3iLDD34sW",
      "_version" : 1,
      "result" : "created",
      "_shards" : {
        "total" : 2,
        "successful" : 1,
        "failed" : 0
      },
      "_seq_no" : 1,
      "_primary_term" : 1
    }

**查询文档**

(1) 语法

GET /index_name/_doc/id

(2) 实例

GET /twitter/_doc/1

结果:

{
      "_index" : "twitter",
      "_type" : "_doc",
      "_id" : "1",
      "_version" : 1,
      "_seq_no" : 0,
      "_primary_term" : 1,
      "found" : true,
      "_source" : {
        "user" : "kimchy",
        "post_date" : "2019-11-15T14:12:12",
        "message" : "trying out Elasticsearch"
      }
    }

**修改文档**

(1) 语法

POST /index_name/_update/id
    {
      "doc": {
        "字段名": "字段值"
      }
    }

(2) 实例

POST /twitter/_update/1
    {
      "doc": {
        "user": "tyshawn"
      }
    }

结果:

GET /twitter/_doc/1
    
    {
      "_index" : "twitter",
      "_type" : "_doc",
      "_id" : "1",
      "_version" : 2,
      "_seq_no" : 1,
      "_primary_term" : 1,
      "found" : true,
      "_source" : {
        "user" : "tyshawn",
        "post_date" : "2019-11-15T14:12:12",
        "message" : "trying out Elasticsearch"
      }
    }

**删除文档**

(1) 语法

DELETE /index_name/_doc/id

(2) 实例

DELETE /twitter/_doc/1

结果:

GET /twitter/_doc/1
    
    {
      "_index" : "twitter",
      "_type" : "_doc",
      "_id" : "1",
      "found" : false
    }

### 批量操作 ###

**批量增删改**

(1) 语法

POST _bulk
    { "index" : { "_index" : "index_name", "_id" : "1" } }
    { "字段名" : "字段值" }
    { "delete" : { "_index" : "index_name", "_id" : "2" } }
    { "create" : { "_index" : "index_name", "_id" : "3" } }
    { "字段名" : "字段值" }
    { "update" : {"_id" : "1", "_index" : "index_name"} }
    { "doc" : {"字段名" : "字段值"} }

index新增文档, 如果文档存在, 则覆盖旧文档, 同时版本号增加. create新增文档, 如果文档存在, 则新增失败.

(2) 实例

POST /_bulk
    {"delete" : {"_index":"twitter","_id":"1"}}
    {"create" :{"_index":"twitter","_id":"2"}}
    {"name":"tyshawn", "age":18}
    {"index":{"_index":"twitter","_id":"3"}}
    {"name":"lee", "age":24}
    {"update":{"_index":"twitter","_id":"2"}}
    {"doc":{"age":30}}

**批量查询**

(1) 语法

GET /_mget
    {
        "docs" : [
            {
                "_index" : "index_name",
                "_id" : "1"
            },
            {
                "_index" : "index_name",
                "_id" : "2"
            }
    	...
        ]
    }

(2) 实例

GET /_mget
    {
      "docs": [
      {
        "_index": "twitter",
        "_id": "2"
      },
      {
        "_index": "twitter",
        "_id": "3"
      }
      ]
    }

结果:

{
      "docs" : [
        {
          "_index" : "twitter",
          "_type" : "_doc",
          "_id" : "2",
          "_version" : 2,
          "_seq_no" : 5,
          "_primary_term" : 1,
          "found" : true,
          "_source" : {
            "name" : "tyshawn",
            "age" : 30
          }
        },
        {
          "_index" : "twitter",
          "_type" : "_doc",
          "_id" : "3",
          "_version" : 1,
          "_seq_no" : 4,
          "_primary_term" : 1,
          "found" : true,
          "_source" : {
            "name" : "lee",
            "age" : 24
          }
        }
      ]
    }

### Java实例 ###

下面介绍Elasticsearch Java Client 的使用, 我们来将上文的实例转化为 Java Client.

(1) main方法

public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("localhost", 9200, "http")));
    
        index(client);
        get(client);
    
        update(client);
        get(client);
    
        delete(client);
        get(client);
    
        bulkOperation(client);
        multiGet(client);
    
        client.close();
    }

新增文档和查询文档请求不要一起执行, 这样会查不到文档, 因为新增文档后需要1s时间进行倒排索引创建, 这也是ES被称为近实时的原因.

(2) 新增文档

private static void index(RestHighLevelClient client) throws IOException {
        XContentBuilder builder = XContentFactory.jsonBuilder();
        builder.startObject();
        builder.field("user", "kimchy");
        builder.timeField("postDate", new Date());
        builder.field("message", "trying out Elasticsearch");
        builder.endObject();
    
        IndexRequest indexRequest = new IndexRequest("twitter").id("1").source(builder);
        client.index(indexRequest, RequestOptions.DEFAULT);
    }

(3) 查询文档

private static void get(RestHighLevelClient client) throws IOException {
        GetRequest getRequest = new GetRequest("twitter", "1");
        GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);
        if (getResponse.isExists()) {
            System.out.println(getResponse.getSourceAsString());
        } else {
            System.out.println("文档不存在");
        }
    }

(3) 修改文档

private static void update(RestHighLevelClient client) throws IOException {
        XContentBuilder builder = XContentFactory.jsonBuilder();
        builder.startObject();
        builder.field("user", "tyshawn");
        builder.endObject();
    
        UpdateRequest updateRequest = new UpdateRequest("twitter", "1").doc(builder);
        client.update(updateRequest, RequestOptions.DEFAULT);
    }

(4) 删除文档

private static void delete(RestHighLevelClient client) throws IOException {
        DeleteRequest deleteRequest = new DeleteRequest("twitter", "1");
        client.delete(deleteRequest, RequestOptions.DEFAULT);
    }

(5) 批量操作文档

private static void bulkOperation(RestHighLevelClient client) throws IOException {
        BulkRequest bulkRequest = new BulkRequest();
        bulkRequest.add(new DeleteRequest("twitter").id("1"));
        bulkRequest.add(new IndexRequest("twitter").id("2").source(XContentType.JSON, "name", "tyshawn", "age", 18));
        bulkRequest.add(new IndexRequest("twitter").id("3").opType(DocWriteRequest.OpType.CREATE).source(XContentType.JSON, "name", "lee", "age", 23));
        bulkRequest.add(new UpdateRequest("twitter", "2").doc(XContentType.JSON, "age", 30));
    
        client.bulk(bulkRequest, RequestOptions.DEFAULT);
    }

(6) 批量查询文档

private static void multiGet(RestHighLevelClient client) throws IOException {
        MultiGetRequest multiGetRequest = new MultiGetRequest();
        multiGetRequest.add(new MultiGetRequest.Item("twitter", "2"));
        multiGetRequest.add(new MultiGetRequest.Item("twitter", "3"));
    
        MultiGetResponse multiGetResponse = client.mget(multiGetRequest, RequestOptions.DEFAULT);
        MultiGetItemResponse[] responses = multiGetResponse.getResponses();
        for (MultiGetItemResponse respons : responses) {
            GetResponse response = respons.getResponse();
            if (response.isExists()) {
                System.out.println(response.getSourceAsString());
            }
        }
    }