You can use prefix query to query data that matches a specified prefix. When a table contains a TEXT string, Tablestore tokenizes the string and matches tokens by using the specified prefix.

Prerequisites

  • The OTSClient instance is initialized. For more information, see Initialization.
  • A data table is created and data is written to the table.
  • A search index is created for the table. For more information, see Create search indexes.

Parameters

Parameter Description
field_name The name of the column used to match the query conditions.
prefix The value of the prefix.

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

query The query type. To use prefix query, set this parameter to PrefixQuery.
table_name The name of the table.
index_name The name of the search index.
limit The maximum number of rows that the current query returns.

To query only the number of matched rows but not detailed data, you can set limit to 0. In this case, Tablestore returns the number of matched rows without data from the table.

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

Query performance is affected when this parameter is set to True.

columns_to_get Specifies whether to return all columns of each matched row. You can configure return_type and column_names for this parameter.
  • If you set return_type to ColumnReturnType.SPECIFIED, you can configure column_names to specify the columns to return.
  • If you set return_type to ColumnReturnType.ALL, all columns are returned.
  • If you set return_type to ColumnReturnType.NONE, only the primary key columns are returned.

Examples

query = PrefixQuery('k', 'key00')
rows, next_token, total_count, is_all_succeed = client.search(
    table_name, index_name, 
    SearchQuery(query, limit=100, get_total_count=True), 
    ColumnsToGet(return_type=ColumnReturnType.ALL)
)