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Tablestore:Wildcard query

Last Updated:Jul 31, 2024

When you perform a wildcard query, you can use the asterisk (*) and question mark (?) wildcard characters in the query to search for data. The asterisk (*) matches a string of any length at, before, or after a search term. The question mark (?) matches a single character in a specific position. The string can start with an asterisk (*) or a question mark (?). For example, if you search for the "table*e" string, "tablestore" can be matched.

If you want to use *word* (equivalent to WHERE field_a LIKE '%word%' in SQL) to query data, you can use fuzzy query for better performance. For more information, see Fuzzy query. If you perform a fuzzy query, the query performance is not compromised when the data volume increases.

Note

If you want to use the NOT LIKE operator, you must use WildcardQuery together with mustNotQueries of BoolQuery.

Prerequisites

Parameters

Parameter

Description

tableName

The name of the data table.

indexName

The name of the search index.

offset

The position from which the current query starts.

limit

The maximum number of rows that you want the current query to return.

queryType

The query type. Set this parameter to TableStore.QueryType.WILDCARD_QUERY.

fieldName

The name of the column that you want to query.

value

The string that contains wildcard characters. The string can be up to 32 characters in length.

getTotalCount

Specifies whether to return the total number of rows that match the query conditions. By default, the value of this parameter is false, which indicates that the total number of rows that meet the query conditions is not returned.

If you set the getTotalCount parameter to true, the query performance is compromised.

columnToGet

Specifies whether to return all columns of each row that meets the query conditions. You can configure returnType and returnNames for this parameter.

  • If you set returnType to TableStore.ColumnReturnType.RETURN_SPECIFIED, you need to configure returnNames to specify the columns that you want to return.

  • If you set the returnType parameter to TableStore.ColumnReturnType.RETURN_ALL, all columns are returned.

  • If you set the returnType parameter to TableStore.ColumnReturnType.RETURN_ALL_FROM_INDEX, all columns in the search index are returned. .

  • If you set the returnType parameter to TableStore.ColumnReturnType.RETURN_NONE, only the primary key columns are returned.

Examples

The following sample code searches for rows in which the value of Col_Keyword matches the "table*e" string.

/**
 * Search the table for rows in which the value of Col_Keyword matches "table*e". 
 */
client.search({
    tableName: TABLE_NAME,
    indexName: INDEX_NAME,
    searchQuery: {
        offset: 0,
        limit: 10, // To query only the number of rows that meet the query conditions without returning specific data, you can set limit to 0. This way, Tablestore returns the number of rows that meet the query conditions without specific data from the table. 
        query: { // Set the query type to TableStore.QueryType.WILDCARD_QUERY. 
            queryType: TableStore.QueryType.WILDCARD_QUERY,
            query: {
                fieldName: "Col_Keyword",
                value: "table*e" // Specify a string that contains one or more wildcard characters in a wildcard query. 
            }
        },
        getTotalCount: true // Specify whether to return the total number of rows that meet the query conditions. The default value of this parameter is false, which indicates that the total number of rows that meet the query conditions is not returned. 
    },
    columnToGet: { // Specify the columns that you want to return. You can set the parameter to RETURN_SPECIFIED to return specified columns, RETURN_ALL to return all columns, RETURN_ALL_FROM_INDEX to return all columns in the search index, or RETURN_NONE to return only the primary key columns. 
        returnType: TableStore.ColumnReturnType.RETURN_ALL
    }
}, function (err, data) {
    if (err) {
        console.log('error:', err);
        return;
    }
    console.log('success:', JSON.stringify(data, null, 2));
});

FAQ

References

  • The following query types are supported by search indexes: term query, terms query, match all query, match query, match phrase query, prefix query, range query, wildcard query, Boolean query, geo query, nested query, vector query, and exists query. You can select a query type to query data based on your business requirements.

    If you want to sort or paginate the rows that meet the query conditions, you can use the sorting and paging feature. For more information, see Sorting and paging.

    If you want to collapse the result set based on a specific column, you can use the collapse (distinct) feature. 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, such as obtaining the extreme values, sum, and total number of rows, you can perform aggregation operations or execute SQL statements. For more information, see Aggregation and SQL query.

  • If you want to quickly 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.