Tablestore：檢索Lastpoint索引

1. 建立多元索引

以下樣本用於為Lastpoint索引建立一個多元索引。樣本情境及資料請參見附錄。

func createSearchIndex(client *tablestore.TableStoreClient) {
	request := &tablestore.CreateSearchIndexRequest{}
	request.TableName = "<LASTPOINT_INDEX_NAME>"
	request.IndexName = "<SEARCH_INDEX_NAME>"
	request.IndexSchema = &tablestore.IndexSchema{
		FieldSchemas: []*tablestore.FieldSchema{
			{
				FieldName:        proto.String("_#h"),
				FieldType:        tablestore.FieldType_KEYWORD,
				Index:            proto.Bool(true),
				EnableSortAndAgg: proto.Bool(true),
			},
			{
				FieldName:        proto.String("_m_name"),
				FieldType:        tablestore.FieldType_KEYWORD,
				Index:            proto.Bool(true),
				EnableSortAndAgg: proto.Bool(true),
			},
			{
				FieldName:        proto.String("_data_source"),
				FieldType:        tablestore.FieldType_KEYWORD,
				Index:            proto.Bool(true),
				EnableSortAndAgg: proto.Bool(true),
			},
			{
				FieldName:        proto.String("_tags"),
				FieldType:        tablestore.FieldType_KEYWORD,
				Index:            proto.Bool(true),
				EnableSortAndAgg: proto.Bool(true),
				IsArray:          proto.Bool(true),
			},
			{
				FieldName:        proto.String("_time"),
				FieldType:        tablestore.FieldType_LONG,
				Index:            proto.Bool(true),
				EnableSortAndAgg: proto.Bool(true),
			},
			{
				FieldName:        proto.String("gps"),
				FieldType:        tablestore.FieldType_GEO_POINT,
				Index:            proto.Bool(true),
				EnableSortAndAgg: proto.Bool(true),
			},
			{
				FieldName:        proto.String("speed"),
				FieldType:        tablestore.FieldType_DOUBLE,
				Index:            proto.Bool(true),
				EnableSortAndAgg: proto.Bool(true),
			},
			{
				FieldName:        proto.String("status"),
				FieldType:        tablestore.FieldType_KEYWORD,
				Index:            proto.Bool(true),
				EnableSortAndAgg: proto.Bool(true),
			},
			{
				FieldName:        proto.String("total_mileage"),
				FieldType:        tablestore.FieldType_LONG,
				Index:            proto.Bool(true),
				EnableSortAndAgg: proto.Bool(true),
			},
			{
				FieldName:        proto.String("remaining_mileage"),
				FieldType:        tablestore.FieldType_LONG,
				Index:            proto.Bool(true),
				EnableSortAndAgg: proto.Bool(true),
			},
		},
	}
	_, err := client.CreateSearchIndex(request)
	if err != nil {
		fmt.Println("Failed to create searchIndex with error:", err)
		return
	}
}

2. 通過多元索引檢索資料

此處以範圍查詢為例介紹多元索引查詢功能的使用。

以下樣本用於通過多元索引檢索Lastpoint索引中speed值大於20.0的行資料。

func RangeQuery(client *tablestore.TableStoreClient, lastpointName string, indexName string) {
	searchRequest := &tablestore.SearchRequest{}
	searchRequest.SetTableName(lastpointName)
	searchRequest.SetIndexName(indexName)
	searchQuery := search.NewSearchQuery()
	rangeQuery := &search.RangeQuery{} //設定查詢類型為RangeQuery。
	rangeQuery.FieldName = "speed" //設定要匹配的欄位
	rangeQuery.GT(20.0)                //設定該欄位的範圍條件為大於20.0。
	searchQuery.SetQuery(rangeQuery)
	//設定按照speed列逆序排序。
	searchQuery.SetSort(&search.Sort{
		[]search.Sorter{
			&search.FieldSort{
				FieldName: "speed",
				Order:     search.SortOrder_DESC.Enum(),
			},
		},
	})
	searchRequest.SetSearchQuery(searchQuery)
	searchRequest.SetColumnsToGet(&tablestore.ColumnsToGet{
		ReturnAll: true,
	})
	searchResponse, err := client.Search(searchRequest)
	if err != nil {
		fmt.Printf("%#v", err)
		return
	}
	fmt.Println("IsAllSuccess: ", searchResponse.IsAllSuccess) //查看返回結果是否完整。
	fmt.Println("RowCount: ", len(searchResponse.Rows))
	for _, row := range searchResponse.Rows {
		jsonBody, err := json.Marshal(row)
		if err != nil {
			panic(err)
		}
		fmt.Println("Row: ", string(jsonBody))
	}
}