You can use prefix query to query data that matches a specified prefix. If the type of a field is TEXT, Tablestore tokenizes the string and matches tokens by using the specified prefix.

Prerequisites

  • A Tablestore client is initialized. For more information, see Initialization.
  • A data table is created. Data is written to the table.
  • A search index is created for the data table. For more information, see Create search indexes.

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.

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.

queryType The query type. To use prefix query, set this parameter to TableStore.QueryType.PREFIX_QUERY.
fieldName The name of the field that you want to match.
prefix The prefix.

If the field used to match the prefix condition is a TEXT field, the field values are tokenized. A row meets the query conditions when at least one token contains the specified prefix.

getTotalCount Specifies 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.

If you set this 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

/**
 * Search the table for rows in which the value of Col_Keyword contains the "hang" prefix, such as "hangzhou". 
 */
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.PREFIX_QUERY. 
            queryType: TableStore.QueryType.PREFIX_QUERY,
            query: {
                fieldName: "Col_Keyword",
                prefix: "hang" // Set the prefix to "hang" to match field values such as "hangzhou" or "hangzhoushi". 
            }
        },
        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 configure the RETURN_SPECIFIED parameter to return specified columns, the RETURN_ALL parameter to return all columns, the RETURN_ALL_FROM_INDEX parameter to return all columns in the search index, or the RETURN_NONE parameter 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));
});