Nested query - Tablestore SDK for Go - Tablestore - Alibaba Cloud Documentation Center

Prerequisites

Install the Tablestore Go SDK and initialize a client.

Description

Each child row in a Nested field is indexed as an independent nested document. A nested query ensures that conditions on multiple child fields match within the same child row and avoids cross-child-row matches.

func (client *tablestore.TableStoreClient) Search(request *tablestore.SearchRequest) (*tablestore.SearchResponse, error)

The following example queries data and returns up to 10 rows and the total number of matched rows.

tableName := "example_table"
indexName := "example_index"

query := &search.NestedQuery{Path: "items", Query: &search.TermQuery{FieldName: "items.name", Term: "alice"}, ScoreMode: search.ScoreMode_Avg}
searchQuery := search.NewSearchQuery().
    SetQuery(query).
    SetLimit(10).
    SetGetTotalCount(true)

response, err := client.Search(&tablestore.SearchRequest{
    TableName:   tableName,
    IndexName:   indexName,
    SearchQuery: searchQuery,
    ColumnsToGet: &tablestore.ColumnsToGet{
        ReturnAllFromIndex: true,
    },
})
if err != nil {
    log.Fatal(err)
}

fmt.Println(response.TotalCount)
fmt.Println(response.Rows)

Parameters

Query request

request is of the tablestore.SearchRequest type and contains the following parameters.

Name	Type	Description
TableName (required)	string	The name of the data table.
IndexName (required)	string	The name of the search index.
SearchQuery (required)	search.SearchQuery	The query condition and common query configurations.
ColumnsToGet (optional)	*tablestore.ColumnsToGet	The return-column configuration. If this parameter is omitted, only primary key columns are returned.
RoutingValues (optional)	[]*tablestore.PrimaryKey	Primary key values for custom routing fields. Omit this parameter if custom routing is not configured.
TimeoutMs (optional)	*int32	The request timeout period in milliseconds.

Query configuration

Create a query configuration by calling search.NewSearchQuery() and configure it by using the following methods.

Name	Type	Description
SetQuery (required)	search.Query	Specifies the query condition.
SetOffset (optional)	int32	Specifies the start position. Default value: 0. For offset-based pagination, Offset + Limit cannot exceed 100,000.
SetLimit (optional)	int32	Specifies the maximum number of rows to return. Default value: 10. Maximum value: 100. A value of 0 returns no rows.
SetCollapse (optional)	*search.Collapse	Collapses query results. For more information, see Collapse query results.
SetSort (optional)	*search.Sort	Specifies the result sort order. For more information, see Sort and paginate results.
SetGetTotalCount (optional)	bool	Specifies whether to count all matched rows. Default value: false.
SetToken (optional)	[]byte	Specifies the NextToken value returned by the previous response. This method clears Sort because the token contains the previous-page sort conditions. Do not specify Offset when you use token-based pagination.
SetSearchFilter (optional)	*search.SearchFilter	Applies a post-query filter. For more information, see Use post-query filters.
Aggregation (optional)	...search.Aggregation	Configures aggregations. For more information, see Aggregation.
GroupBy (optional)	...search.GroupBy	Configures grouping. For more information, see Aggregation.

Query condition

The query is of the search.NestedQuery type and contains the following parameters.

Name	Type	Description
Path (required)	string	The path of the Nested field.
Query (required)	search.Query	The query on child fields. Use a full path such as `items.name` for a child field.
ScoreMode (optional)	search.ScoreMode	The method used to combine scores from matching child rows.
InnerHits (optional)	*search.InnerHits	Returns matching child rows and can configure pagination, sorting, and highlighting for the child rows.

Inner hits configuration

InnerHits contains the following parameters.

Name	Type	Description
Offset (optional)	*int32	The start position of matching child rows.
Limit (optional)	*int32	The number of matching child rows to return. Default value: 3.
Sort (optional)	*search.Sort	The sort order of matching child rows.
Highlight (optional)	*search.Highlight	The summary and highlighting configuration for Nested child fields. For more information, see Summary and highlighting.

Columns to return

request.ColumnsToGet is of the tablestore.ColumnsToGet type and contains the following parameters.

Name	Type	Description
Columns (optional)	[]string	The attribute columns to return. This parameter takes effect only when ReturnAll and ReturnAllFromIndex are both false.
ReturnAll (optional)	bool	Specifies whether to return all attribute columns in the data table. Default value: false.
ReturnAllFromIndex (optional)	bool	Specifies whether to return all indexed attribute columns. Default value: false. Do not set this parameter and ReturnAll to true at the same time.

Response

The Search method returns a tablestore.SearchResponse value. The following table describes the core business fields.

Name	Type	Description
TotalCount	int64	The total number of matched rows. The value depends on SetGetTotalCount.
Rows	[]*tablestore.Row	The rows returned by the current query. The number does not exceed the value specified by SetLimit.
SearchHits	[]*tablestore.SearchHit	The search hits. Read this field when you use highlighting, nested inner hits, or relevance scores.
NextToken	[]byte	The token for the next page. If the value is not empty, pass it to the next query.
IsAllSuccess	bool	Indicates whether all index partitions were queried. If the value is false, partial results are returned and TotalCount may be less than the actual number of matched rows.
AggregationResults	search.AggregationResults	The aggregation results.
GroupByResults	search.GroupByResults	The grouping results.