Example #1
0
func ExampleSearchResult() {
	client, err := elastic.NewClient()
	if err != nil {
		panic(err)
	}

	// Do a search
	searchResult, err := client.Search().Index("twitter").Query(elastic.NewMatchAllQuery()).Do()
	if err != nil {
		panic(err)
	}

	// searchResult is of type SearchResult and returns hits, suggestions,
	// and all kinds of other information from Elasticsearch.
	fmt.Printf("Query took %d milliseconds\n", searchResult.TookInMillis)

	// Each is a utility function that iterates over hits in a search result.
	// It makes sure you don't need to check for nil values in the response.
	// However, it ignores errors in serialization. If you want full control
	// over iterating the hits, see below.
	var ttyp Tweet
	for _, item := range searchResult.Each(reflect.TypeOf(ttyp)) {
		t := item.(Tweet)
		fmt.Printf("Tweet by %s: %s\n", t.User, t.Message)
	}
	fmt.Printf("Found a total of %d tweets\n", searchResult.TotalHits())

	// Here's how you iterate hits with full control.
	if searchResult.Hits != nil {
		fmt.Printf("Found a total of %d tweets\n", searchResult.Hits.TotalHits)

		// Iterate through results
		for _, hit := range searchResult.Hits.Hits {
			// hit.Index contains the name of the index

			// Deserialize hit.Source into a Tweet (could also be just a map[string]interface{}).
			var t Tweet
			err := json.Unmarshal(*hit.Source, &t)
			if err != nil {
				// Deserialization failed
			}

			// Work with tweet
			fmt.Printf("Tweet by %s: %s\n", t.User, t.Message)
		}
	} else {
		// No hits
		fmt.Print("Found no tweets\n")
	}
}
Example #2
0
func ExampleAggregations() {
	// Get a client to the local Elasticsearch instance.
	client, err := elastic.NewClient()
	if err != nil {
		// Handle error
		panic(err)
	}

	// Create an aggregation for users and a sub-aggregation for a date histogram of tweets (per year).
	timeline := elastic.NewTermsAggregation().Field("user").Size(10).OrderByCountDesc()
	histogram := elastic.NewDateHistogramAggregation().Field("created").Interval("year")
	timeline = timeline.SubAggregation("history", histogram)

	// Search with a term query
	searchResult, err := client.Search().
		Index("twitter").                  // search in index "twitter"
		Query(elastic.NewMatchAllQuery()). // return all results, but ...
		SearchType("count").               // ... do not return hits, just the count
		Aggregation("timeline", timeline). // add our aggregation to the query
		Pretty(true).                      // pretty print request and response JSON
		Do()                               // execute
	if err != nil {
		// Handle error
		panic(err)
	}

	// Access "timeline" aggregate in search result.
	agg, found := searchResult.Aggregations.Terms("timeline")
	if !found {
		log.Fatalf("we sould have a terms aggregation called %q", "timeline")
	}
	for _, userBucket := range agg.Buckets {
		// Every bucket should have the user field as key.
		user := userBucket.Key

		// The sub-aggregation history should have the number of tweets per year.
		histogram, found := userBucket.DateHistogram("history")
		if found {
			for _, year := range histogram.Buckets {
				fmt.Printf("user %q has %d tweets in %q\n", user, year.DocCount, year.KeyAsString)
			}
		}
	}
}