Use Tablestore SDK for .NET to perform a term query - Tablestore

Use term query to find rows where a specific field exactly matches a keyword. The keyword is not tokenized. For TEXT fields, Tablestore tokenizes the field value and matches the keyword against each token — a row qualifies if any token is an exact match.

Prerequisites

An OTSClient instance is initialized. For more information, see Initialize an OTSClient instance.
A data table is created and data is written to the data table. For more information, see Create data tables and Write data.
A search index is created for the data table. For more information, see Create search indexes.

Parameters

Parameter	Description
FieldName	The name of the field to match.
Term	The keyword to match against field values. The keyword is not tokenized — it is matched as-is against the full field value or, for TEXT fields, against each token. For TEXT fields, Tablestore tokenizes the field value and checks whether any token exactly matches the keyword. For example, if a TEXT field contains "tablestore is cool", the value is tokenized into "tablestore", "is", and "cool". Specifying any one of these as the keyword returns the row.
GetTotalCount	Specifies whether to return the total number of matching rows. Defaults to `false`. Setting this to `true` reduces query performance.
Query	The query type. Set to `TermQuery` for term query.
TableName	The name of the data table.
IndexName	The name of the search index.
ColumnsToGet	Specifies which columns to return for matching rows. Configure `ReturnAll`, `Columns`, or `ReturnAllFromIndex`. The default value of ReturnAll is false, which specifies that not all columns are returned. You can use one of the following methods to specify the columns that you want to return. If you do not use the following methods to specify the columns that you want to return, only the primary key columns are returned. Configure Columns to specify the columns that you want to return. Set ReturnAllFromIndex to true to return all columns from the search index. If you set ReturnAll to true, all columns are returned.

Examples

The following example queries rows where the Keyword_type_col field exactly matches SearchIndex.

/// <summary>
/// Query rows where Keyword_type_col exactly matches "SearchIndex".
/// </summary>
/// <param name="otsClient"></param>
public static void TermQuery(OTSClient otsClient)
{
    var searchQuery = new SearchQuery();
    // Return the total number of matching rows.
    searchQuery.GetTotalCount = true;
    // Match rows where Keyword_type_col equals "SearchIndex".
    searchQuery.Query = new TermQuery("Keyword_type_col", new ColumnValue("SearchIndex"));

    var request = new SearchRequest(TableName, IndexName, searchQuery);
    // Return all columns from the search index.
    // To return specific columns: Columns = new List<string>() { Long_type_col, Text_type_col, Keyword_type_col }
    // To return all columns from the data table: ReturnAll = true
    request.ColumnsToGet = new ColumnsToGet()
    {
        ReturnAllFromIndex = true
    };

    var response = otsClient.Search(request);
    // Check NextToken for paginated results.
}

FAQ

References

When you use a search index to query data, you can use the following query methods: term query, terms query, match all query, match query, match phrase query, prefix query, range query, wildcard query, Boolean query, geo query, nested query, and exists query. You can use different query methods to query data from multiple dimensions based on your business requirements.
You can sort or paginate rows that meet the query conditions by using the sorting and paging features. For more information, see Sorting and paging.
You can use the collapse (distinct) feature to collapse the result set based on a specific column. This way, data of the specified type appears only once in the query results. For more information, see Collapse (distinct).
If you want to analyze data in a data table, you can use the aggregation feature of the Search operation or execute SQL statements. For example, you can obtain the minimum and maximum values, sum, and total number of rows. For more information, see Aggregation and SQL query.
If you want to obtain all rows that meet the query conditions without the need to sort the rows, you can call the ParallelScan and ComputeSplits operations to use the parallel scan feature. For more information, see Parallel scan.