Use Tablestore SDK for Python to query the total number of rows in a table and return multiple random rows - Tablestore

You can use match all query to match all rows in a table to query the total number of rows in the table and return multiple random rows.

Prerequisites

The OTSClient is initialized. For more information, see Initialize an OTSClient instance.
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
query	The type of the query. Set the query parameter to MatchAllQuery.
table_name	The name of the data table.
index_name	The name of the search index.
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.
get_total_count	Specifies whether to return the total number of rows that meet the query conditions. Default value: false. The value of false specifies 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.
columns_to_get	Specifies whether to return all columns of each row that meets the query conditions. If you set return_type to ColumnReturnType.SPECIFIED, you can use column_names to specify the columns that you want 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

The following sample code provides an example on how to query the total number of rows in a table:

Tablestore SDK for Python V5.2.1 or later

By default, if you use Tablestore SDK for Python V5.2.1 or later to perform a match all query, a SearchResponse object is returned. The following code provides a sample request:

query=MatchAllQuery()
all_rows=[]
next_token=None
first_page=True

while first_page or next_token:
    search_response=client.search(table_name, index_name,
        SearchQuery(query,next_token=next_token,limit=100,get_total_count=True),
        columns_to_get=ColumnsToGet(['k','t','g','ka','la'],ColumnReturnType.SPECIFIED))
    all_rows.extend(search_response.rows)
    first_page=False
for row in all_rows:
    print(row)

print('Totalrows:', len(all_rows))

You can use the following sample request to return results of the Tuple type:

query=MatchAllQuery()
all_rows=[]
next_token=None
first_page=True

while first_page or next_token:
    rows, next_token, total_count, is_all_succeed, agg_results, group_by_results =client.search(table_name, index_name,
        SearchQuery(query,next_token=next_token,limit=100,get_total_count=True),
        columns_to_get=ColumnsToGet(['k','t','g','ka','la'],ColumnReturnType.SPECIFIED)).v1_response()
    all_rows.extend(rows)
    first_page=False
for row in all_rows:
    print(row)

print('Totalrows:', len(all_rows))

Tablestore SDK for Python of a version earlier than V5.2.1

If you use a version of Tablestore SDK for Python that is earlier than V5.2.1 to perform a match all query, results of the TUPLE type are returned by default. The following sample code provides a sample request:

query=MatchAllQuery()
all_rows=[]
next_token=None
first_page=True
while first_page or next_token:
    rows, next_token, total_count, is_all_succeed = client.search(table_name, index_name,
        SearchQuery(query, next_token=next_token, limit=100, get_total_count=True),
        columns_to_get=ColumnsToGet(['k', 't', 'g', 'ka', 'la'], ColumnReturnType.SPECIFIED))
    all_rows.extend(rows)
    first_page=False
for row in all_rows:
    print(row)

print('Total rows:', len(all_rows))