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Golang使用Elasticsearch

创建es.go文件
根据elasticsearch版本拉取对应的go包:github.com/elastic/go-elasticsearch
API文档:https://pkg.go.dev/github.com/elastic/go-elasticsearch/v6@v6.8.5/esapi?tab=doc

package esimport (    "bytes"    "context"    "encoding/json"    "fmt"    "github.com/elastic/go-elasticsearch/v6"    "log")func failOnError(err error, msg string) {    if err != nil {        log.Fatalf("%s: %s", msg, err)    }}

Index 在索引中创建或更新文档
索引不存在的情况下,会自动创建索引。
默认的_type(类型)是_doc,下面是指定doc类型创建添加的。

func Index() {    addresses := []string{"http://127.0.0.1:9200", "http://127.0.0.1:9201"}    config := elasticsearch.Config{        Addresses:             addresses,        Username:              "",        Password:              "",        CloudID:               "",        APIKey:                "",    }    // new client    es, err := elasticsearch.NewClient(config)    failOnError(err, "Error creating the client")    // Index creates or updates a document in an index    var buf bytes.Buffer    doc := map[string]interface{}{        "title": "你看到外面的世界是什么样的?",        "content": "外面的世界真的很精彩",    }    if err := json.NewEncoder(&buf).Encode(doc); err != nil {        failOnError(err, "Error encoding doc")    }    res, err := es.Index("demo", &buf, es.Index.WithDocumentType("doc"))    if err != nil {        failOnError(err, "Error Index response")    }    defer res.Body.Close()    fmt.Println(res.String())}

Search 搜索

func Search() {    addresses := []string{"http://127.0.0.1:9200", "http://127.0.0.1:9201"}    config := elasticsearch.Config{        Addresses:             addresses,        Username:              "",        Password:              "",        CloudID:               "",        APIKey:                "",    }    // new client    es, err := elasticsearch.NewClient(config)    failOnError(err, "Error creating the client")    // info    res, err := es.Info()    failOnError(err, "Error getting response")    fmt.Println(res.String())    // search - highlight    var buf bytes.Buffer    query := map[string]interface{}{        "query": map[string]interface{}{            "match": map[string]interface{}{                "title": "中国",            },        },        "highlight": map[string]interface{}{            "pre_tags" : []string{"<font color='red'>"},            "post_tags" : []string{"</font>"},            "fields" : map[string]interface{}{                "title" : map[string]interface{}{},            },        },    }    if err := json.NewEncoder(&buf).Encode(query); err != nil {        failOnError(err, "Error encoding query")    }    // Perform the search request.    res, err = es.Search(        es.Search.WithContext(context.Background()),        es.Search.WithIndex("demo"),        es.Search.WithBody(&buf),        es.Search.WithTrackTotalHits(true),        es.Search.WithPretty(),    )    if err != nil {        failOnError(err, "Error getting response")    }    defer res.Body.Close()    fmt.Println(res.String())}

DeleteByQuery 通过匹配条件删除文档

func DeleteByQuery() {    addresses := []string{"http://127.0.0.1:9200", "http://127.0.0.1:9201"}    config := elasticsearch.Config{        Addresses:             addresses,        Username:              "",        Password:              "",        CloudID:               "",        APIKey:                "",    }    // new client    es, err := elasticsearch.NewClient(config)    failOnError(err, "Error creating the client")    // DeleteByQuery deletes documents matching the provided query    var buf bytes.Buffer    query := map[string]interface{}{        "query": map[string]interface{}{            "match": map[string]interface{}{                "title": "外面",            },        },    }    if err := json.NewEncoder(&buf).Encode(query); err != nil {        failOnError(err, "Error encoding query")    }    index := []string{"demo"}    res, err := es.DeleteByQuery(index, &buf)    if err != nil {        failOnError(err, "Error delete by query response")    }    defer res.Body.Close()    fmt.Println(res.String())}

Delete通过_id删除文档

func Delete() {    addresses := []string{"http://127.0.0.1:9200", "http://127.0.0.1:9201"}    config := elasticsearch.Config{        Addresses:             addresses,        Username:              "",        Password:              "",        CloudID:               "",        APIKey:                "",    }    // new client    es, err := elasticsearch.NewClient(config)    failOnError(err, "Error creating the client")    // Delete removes a document from the index    res, err := es.Delete("demo", "POcKSHIBX-ZyL96-ywQO")    if err != nil {        failOnError(err, "Error delete by id response")    }    defer res.Body.Close()    fmt.Println(res.String())}

Create 添加文档(需要指定_id,_id已存在返回409)

func Create() {    addresses := []string{"http://127.0.0.1:9200", "http://127.0.0.1:9201"}    config := elasticsearch.Config{        Addresses:             addresses,        Username:              "",        Password:              "",        CloudID:               "",        APIKey:                "",    }    // new client    es, err := elasticsearch.NewClient(config)    failOnError(err, "Error creating the client")    // Create creates a new document in the index.    // Returns a 409 response when a document with a same ID already exists in the index.    var buf bytes.Buffer    doc := map[string]interface{}{        "title": "你看到外面的世界是什么样的?",        "content": "外面的世界真的很精彩",    }    if err := json.NewEncoder(&buf).Encode(doc); err != nil {        failOnError(err, "Error encoding doc")    }    res, err := es.Create("demo", "esd", &buf, es.Create.WithDocumentType("doc"))    if err != nil {        failOnError(err, "Error create response")    }    defer res.Body.Close()    fmt.Println(res.String())}

Get 通过id获取文档

func Get() {    addresses := []string{"http://127.0.0.1:9200", "http://127.0.0.1:9201"}    config := elasticsearch.Config{        Addresses:             addresses,        Username:              "",        Password:              "",        CloudID:               "",        APIKey:                "",    }    // new client    es, err := elasticsearch.NewClient(config)    failOnError(err, "Error creating the client")    res, err := es.Get("demo", "esd")    if err != nil {        failOnError(err, "Error get response")    }    defer res.Body.Close()    fmt.Println(res.String())}

Update 通过_id更新文档

func Update() {    addresses := []string{"http://127.0.0.1:9200", "http://127.0.0.1:9201"}    config := elasticsearch.Config{        Addresses:             addresses,        Username:              "",        Password:              "",        CloudID:               "",        APIKey:                "",    }    // new client    es, err := elasticsearch.NewClient(config)    failOnError(err, "Error creating the client")    // Update updates a document with a script or partial document.    var buf bytes.Buffer    doc := map[string]interface{}{        "doc": map[string]interface{}{            "title": "更新你看到外面的世界是什么样的?",            "content": "更新外面的世界真的很精彩",        },    }    if err := json.NewEncoder(&buf).Encode(doc); err != nil {        failOnError(err, "Error encoding doc")    }    res, err := es.Update("demo", "esd", &buf, es.Update.WithDocumentType("doc"))    if err != nil {        failOnError(err, "Error Update response")    }    defer res.Body.Close()    fmt.Println(res.String())}

UpdateByQuery 通过匹配条件更新文档

func UpdateByQuery() {    addresses := []string{"http://127.0.0.1:9200", "http://127.0.0.1:9201"}    config := elasticsearch.Config{        Addresses:             addresses,        Username:              "",        Password:              "",        CloudID:               "",        APIKey:                "",    }    // new client    es, err := elasticsearch.NewClient(config)    failOnError(err, "Error creating the client")    // UpdateByQuery performs an update on every document in the index without changing the source,    // for example to pick up a mapping change.    index := []string{"demo"}    var buf bytes.Buffer    doc := map[string]interface{}{        "query": map[string]interface{}{            "match": map[string]interface{}{                "title": "外面",            },        },        // 根据搜索条件更新title        /*        "script": map[string]interface{}{            "source": "ctx._source['title']='更新你看到外面的世界是什么样的?'",        },         */        // 根据搜索条件更新title、content        /*        "script": map[string]interface{}{            "source": "ctx._source=params",            "params": map[string]interface{}{                "title": "外面的世界真的很精彩",                "content": "你看到外面的世界是什么样的?",            },            "lang": "painless",        },         */        // 根据搜索条件更新title、content        "script": map[string]interface{}{            "source": "ctx._source.title=params.title;ctx._source.content=params.content;",            "params": map[string]interface{}{                "title": "看看外面的世界真的很精彩",                "content": "他们和你看到外面的世界是什么样的?",            },            "lang": "painless",        },    }    if err := json.NewEncoder(&buf).Encode(doc); err != nil {        failOnError(err, "Error encoding doc")    }    res, err := es.UpdateByQuery(        index,        es.UpdateByQuery.WithDocumentType("doc"),        es.UpdateByQuery.WithBody(&buf),        es.UpdateByQuery.WithContext(context.Background()),        es.UpdateByQuery.WithPretty(),        )    if err != nil {        failOnError(err, "Error Update response")    }    defer res.Body.Close()    fmt.Println(res.String())}

文章来源:智云一二三科技

文章标题:Golang使用Elasticsearch

文章地址:https://www.zhihuclub.com/780.shtml

关于作者: 智云科技

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