This topic describes how to use nested query to query the child row data of nested columns. You cannot directly query nested fields. You must specify the NestedQuery object. In NestedQuery, you must specify the path of a nested column and a subquery. The subquery can be of any type.

Prerequisites

  • The OTSClient instance 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 table. For more information, see Create search indexes.

Parameters

Parameter Description
table_name The name of the table.
index_name The name of the search index.
path The path of the subcolumn in the nested column. The path is similar to the tree structure. For example, news.title indicates the title subcolumn in the nested news column.
query The query on the subcolumn in the nested column. The query can be of any query type.
score_mode Specifies which value is used to calculate the score when a column contains multiple values.

Examples

The following code provides an example on how to search the nested.nested_keyword column for data that matches "sub": 

$request = array(
    'table_name' => 'php_sdk_test',
    'index_name' => 'php_sdk_test_search_index',
    'search_query' => array(
        'offset' => 0,
        'limit' => 2,
        'get_total_count' => true,
        'query' => array(
            'query_type' => QueryTypeConst::NESTED_QUERY,
            'score_mode' => ScoreModeConst::SCORE_MODE_AVG,
            'query' => array(
                'path' => "nested",
                'query' => array(
                    'query_type' => QueryTypeConst::TERM_QUERY,
                    'query' => array(
                        'field_name' => 'nested.nested_keyword',
                        'term' => 'sub'
                    )
                )
            )
        ),
        'sort' => array(
            array(
                'field_sort' => array(
                    'field_name' => 'nested.nested_long',
                    'order' => SortOrderConst::SORT_ORDER_DESC,
                    'nested_filter' => array(
                        'path' => "nested",
                        'query' => array(
                            'query_type' => QueryTypeConst::TERM_QUERY,
                            'query' => array(
                                'field_name' => 'nested.nested_keyword',
                                'term' => 'sub'
                            )
                        )
                    )
                )
            ),
        )
    ),
    'columns_to_get' => array(
        'return_type' => ColumnReturnTypeConst::RETURN_SPECIFIED,
        'return_names' => array('nested')
    )
);
$response = $otsClient->search($request);