Go操作Elasticsearch
<h4 id="安装es">安装ES</h4><h5 id="拉取es到本地">拉取es到本地</h5>
<pre><code class="language-go">docker pull docker.elastic.co/elasticsearch/elasticsearch:7.3.0
</code></pre>
<h5 id="创建一个网络">创建一个网络</h5>
<pre><code class="language-go">docker network create esnet
</code></pre>
<h5 id="启动容器">启动容器</h5>
<pre><code class="language-go">docker run --name es-p 9200:9200 -p 9300:9300--network esnet -e "discovery.type=single-node" bdaab402b220
</code></pre>
<h5 id="安装elistichd">安装ElisticHD</h5>
<pre><code class="language-go">docker run -p 9800:9800 -d --link es:demo--network esnet -e "discovery.type=single-node"containerize/elastichd
</code></pre>
<p><img src="https://img2020.cnblogs.com/blog/1871335/202007/1871335-20200728151228132-403069436.png" alt="" loading="lazy"></p>
<h4 id="下载依赖库">下载依赖库</h4>
<pre><code class="language-go"> go get github.com/olivere/elastic/v7
</code></pre>
<h4 id="操作案例">操作案例</h4>
<h5 id="创建索引">创建索引</h5>
<pre><code class="language-go">package main
import (
"context"
"fmt"
"github.com/olivere/elastic"
)
var client *elastic.Client
var host = "http://192.168.43.176:9200"
type Employee struct {
FirstName string `json:"first_name"`
LastNamestring `json:"last_name"`
Age int `json:"age"`
About string `json:"about"`
Interests []string `json:"interests"`
}
//初始化
func init() {
//errorlog := log.New(os.Stdout, "APP", log.LstdFlags)
var err error
//这个地方有个小坑 不加上elastic.SetSniff(false) 会连接不上
client, err = elastic.NewClient(elastic.SetSniff(false), elastic.SetURL(host))
if err != nil {
panic(err)
}
_,_,err = client.Ping(host).Do(context.Background())
if err != nil {
panic(err)
}
//fmt.Printf("Elasticsearch returned with code %d and version %s\n", code, info.Version.Number)
_,err = client.ElasticsearchVersion(host)
if err != nil {
panic(err)
}
//fmt.Printf("Elasticsearch version %s\n", esversion)
}
//创建
func create() {
//使用结构体
e1 := Employee{"Jane", "Smith", 32, "I like to collect rock albums", []string{"music"}}
put1, err := client.Index().
Index("megacorp").
Type("employee").
Id("1").
BodyJson(e1).
Do(context.Background())
if err != nil {
panic(err)
}
fmt.Printf("Indexed tweet %s to index s%s, type %s\n", put1.Id, put1.Index, put1.Type)
//使用字符串
e2 := `{"first_name":"John","last_name":"Smith","age":25,"about":"I love to go rock climbing","interests":["sports","music"]}`
put2, err := client.Index().
Index("megacorp").
Type("employee").
Id("2").
BodyJson(e2).
Do(context.Background())
if err != nil {
panic(err)
}
fmt.Printf("Indexed tweet %s to index s%s, type %s\n", put2.Id, put2.Index, put2.Type)
e3 := `{"first_name":"Douglas","last_name":"Fir","age":35,"about":"I like to build cabinets","interests":["forestry"]}`
put3, err := client.Index().
Index("megacorp").
Type("employee").
Id("3").
BodyJson(e3).
Do(context.Background())
if err != nil {
panic(err)
}
fmt.Printf("Indexed tweet %s to index s%s, type %s\n", put3.Id, put3.Index, put3.Type)
}
func main(){
create()
}
</code></pre>
<h5 id="查找">查找</h5>
<pre><code class="language-go">package main
import (
"context"
"encoding/json"
"fmt"
"github.com/olivere/elastic"
)
var client *elastic.Client
var host = "http://192.168.43.176:9200"
type Employee struct {
FirstName string `json:"first_name"`
LastNamestring `json:"last_name"`
Age int `json:"age"`
About string `json:"about"`
Interests []string `json:"interests"`
}
//初始化
func init() {
//errorlog := log.New(os.Stdout, "APP", log.LstdFlags)
var err error
//这个地方有个小坑 不加上elastic.SetSniff(false) 会连接不上
client, err = elastic.NewClient(elastic.SetSniff(false), elastic.SetURL(host))
if err != nil {
panic(err)
}
_, _, err = client.Ping(host).Do(context.Background())
if err != nil {
panic(err)
}
//fmt.Printf("Elasticsearch returned with code %d and version %s\n", code, info.Version.Number)
_, err = client.ElasticsearchVersion(host)
if err != nil {
panic(err)
}
//fmt.Printf("Elasticsearch version %s\n", esversion)
}
//查找
func gets() {
//通过id查找
get1, err := client.Get().Index("megacorp").Type("employee").Id("2").Do(context.Background())
if err != nil {
panic(err)
}
if get1.Found {
fmt.Printf("Got document %s in version %d from index %s, type %s\n", get1.Id, get1.Version, get1.Index, get1.Type)
var bb Employee
err := json.Unmarshal(get1.Source, &bb)
if err != nil {
fmt.Println(err)
}
fmt.Println(bb.FirstName)
fmt.Println(string(get1.Source))
}
}
func main() {
//create()
gets()
}
</code></pre>
<h5 id="删除">删除</h5>
<pre><code class="language-go">//删除
func delete() {
res, err := client.Delete().Index("megacorp").
Type("employee").
Id("1").
Do(context.Background())
if err != nil {
println(err.Error())
return
}
fmt.Printf("delete result %s\n", res.Result)
}
func main() {
//create()
//gets()
delete()
}
</code></pre>
<h5 id="修改">修改</h5>
<pre><code class="language-go">//修改
func update() {
res, err := client.Update().
Index("megacorp").
Type("employee").
Id("2").
Doc(mapinterface{}{"age": 88}).
Do(context.Background())
if err != nil {
println(err.Error())
}
fmt.Printf("update age %s\n", res.Result)
}
func main() {
//create()
//gets()
//delete()
update()
}
</code></pre>
<h5 id="搜索">搜索</h5>
<pre><code class="language-go">////搜索
func query() {
var res *elastic.SearchResult
var err error
//取所有
res, err = client.Search("megacorp").Type("employee").Do(context.Background())
printEmployee(res, err)
//字段相等
q := elastic.NewQueryStringQuery("last_name:Smith")
res, err = client.Search("megacorp").Type("employee").Query(q).Do(context.Background())
if err != nil {
println(err.Error())
}
printEmployee(res, err)
//条件查询
//年龄大于30岁的
boolQ := elastic.NewBoolQuery()
boolQ.Must(elastic.NewMatchQuery("last_name", "smith"))
boolQ.Filter(elastic.NewRangeQuery("age").Gt(30))
res, err = client.Search("megacorp").Type("employee").Query(q).Do(context.Background())
printEmployee(res, err)
//短语搜索 搜索about字段中有 rock climbing
matchPhraseQuery := elastic.NewMatchPhraseQuery("about", "rock climbing")
res, err = client.Search("megacorp").Type("employee").Query(matchPhraseQuery).Do(context.Background())
printEmployee(res, err)
//分析 interests
aggs := elastic.NewTermsAggregation().Field("interests")
res, err = client.Search("megacorp").Type("employee").Aggregation("all_interests", aggs).Do(context.Background())
printEmployee(res, err)
}
//
////简单分页
func list(size,page int) {
if size < 0 || page < 1 {
fmt.Printf("param error")
return
}
res,err := client.Search("megacorp").
Type("employee").
Size(size).
From((page-1)*size).
Do(context.Background())
printEmployee(res, err)
}
//
//打印查询到的Employee
func printEmployee(res *elastic.SearchResult, err error) {
if err != nil {
print(err.Error())
return
}
var typ Employee
for _, item := range res.Each(reflect.TypeOf(typ)) { //从搜索结果中取数据的方法
t := item.(Employee)
fmt.Printf("%#v\n", t)
}
}
func main() {
//create()
//gets()
//delete()
//update()
gets()
query()
list(2,1)
}
</code></pre><br><br>
来源：https://www.cnblogs.com/you-men/p/13391265.html
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