golang语言中简单操作es几个例子

 使用库(olivere/elastic/v7)操作es

1、初始化es操作客户端

var err error
EsClient, err = elastic.NewClient(
	elastic.SetSniff(false),
	elastic.SetURL(hosts...),
	elastic.SetBasicAuth(username, password),
	elastic.SetTraceLog(new(tracelog)),//打印查询语句，调试时可以使用
)
if err != nil {
	zap.L().Error(err.Error())
}

type tracelog struct{}

func (tracelog) Printf(format string, v ...interface{}) {
	fmt.Printf(format, v...)
}

2、使用must查询数据

query := elastic.NewBoolQuery()
query.Must(elastic.NewTermQuery(查询字段, 查询值)
res, err := EsClient.Search().Index(index).Query(query).From(0).Size(10).Do(context.Background())
	if err != nil {
		return nil, err
	}
	if res == nil || res.Hits == nil {
		return nil, nil
	}
	rows := make([]map[string]interface{}, 0)
	for _, hit := range res.Hits.Hits {
		var item = make(map[string]interface{})
		jsonByte, marErr := hit.Source.MarshalJSON()

		if marErr == nil {
			err := json.Unmarshal(jsonByte, &item)
			if err != nil {
				return nil, err
			}
			rows = append(rows, item)
		}
	}

3、terms、matchPhraseQuery、rangeQuery

elastic.NewMatchPhraseQuery
elastic.NewRangeQuery(字段).Gte(值).Lte(值)
elastic.NewTermQuery(字段, 值)

4、查询后，根据字段排序

sortQuery := elastic.NewFieldSort(orderField + ".keyword")
	if sortType == "asc" {
		sortQuery = sortQuery.Asc()
	} else {
		sortQuery = sortQuery.Desc()
	}
res, err := EsClient.Search().Index(index).Query(query).From(0).Size(10).SortBy(sortQuery).Do(context.Background())