Collapse query results - Tablestore SDK for Go - Tablestore

Use the Tablestore SDK for Go to collapse query results by a field and return one row for each distinct field value.

Prerequisites

Install the Tablestore Go SDK and initialize a client.

Description

Collapse can be combined with any query type. It groups query results by a field value and returns the first sorted row from each group. TotalCount remains the number of matched rows before collapse, and the total number of groups after collapse cannot be obtained. Sorting and aggregation must be enabled for the collapse field. Long, Double, and Keyword fields are supported, but array fields are not supported.

Important

A collapse query supports only Offset- and Limit-based pagination and does not support token-based pagination. Offset + Limit cannot exceed 100,000, so up to 100,000 groups can be returned.
If aggregation and collapse are used together, aggregation is calculated over the result set before collapse.

searchQuery := search.NewSearchQuery().
    SetQuery(&search.MatchAllQuery{}).
    SetCollapse(&search.Collapse{FieldName: "category"}).
    SetGetTotalCount(true)

response, err := client.Search(&tablestore.SearchRequest{
    TableName:   "example_table",
    IndexName:   "example_index",
    SearchQuery: searchQuery,
})
if err != nil {
    log.Fatal(err)
}

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

Parameters

Name	Type	Description
FieldName (required)	string	The field used to collapse results.

Response

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.
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.