MongoDB C驱动程序不返回任何聚合查询结果

Question

我有以下SQL查询：

SELECT SUM（“PAYMENT_HISTORY”。“AMOUNT_PAID”）FROM“PAYMENT_HISTORY”WHERE（（“PAYMENT_HISTORY”.YEAR＆gt; = 2011）AND（“PAYMENT_HISTORY”.YEAR＆lt; = 2013）AND（“PAYMENT_HISTORY”。“ AMOUNT_PAID“＆gt; = 500.0））

从MongoDB shell运行转换后的相同SQL，它返回值。

db.PAYMENT_HISTORY.aggregate（   {$ match：{$ and：[{YEAR：{$ gte：2011}}，{YEAR：{$ lte：2013}}，{AMOUNT_PAID：{$ gte：500.00}}]}}，   {$ group：{_ id：“POLICY_ID”，总计：{$ sum：“$ AMOUNT_PAID”}}}  ）

当我尝试运行MongoDB C驱动程序时，它不会返回任何结果。

int status = mongo_client( mNoSQLConnection, "127.0.0.1", 27017 );
if (status != MONGO_OK){
    switch (mNoSQLConnection->err) {
        case MONGO_CONN_NO_SOCKET:  printf( "no socket\n" ); 
        case MONGO_CONN_FAIL:       printf( "connection failed\n" ); 
        case MONGO_CONN_NOT_MASTER: printf( "not master\n" ); 
    }
}
else{
    bson query[1], b_result[1];
    mongo_cursor cursor[1];
    bson_init( query );
        bson_append_string(query, "aggregate", "PAYMENT_HISTORY");
            bson_append_start_object(query, "$match");
                bson_append_start_array(query, "$and");
                        bson_append_start_object(query, "$gte");
                            bson_append_int(query, "YEAR", 2011);
                        bson_append_finish_object(query);
                        bson_append_start_object(query, "$lte");
                            bson_append_int(query, "YEAR", 2013);
                        bson_append_finish_object(query);
                        bson_append_start_object(query, "$gte");
                            bson_append_double(query, "AMOUNT_PAID", 500.00);
                        bson_append_finish_object(query);
                bson_append_finish_array(query);
            bson_append_finish_object(query);
            bson_append_start_object(query, "$group");
                bson_append_string(query, "_id", "POLICY_ID");
                bson_append_string(query, "total", "total");
                    bson_append_start_object(query, "$sum");
                        bson_append_start_object(query, "$AMOUNT_PAID");
                        bson_append_finish_object(query);
                    bson_append_finish_object(query);
            bson_append_finish_object(query);
    bson_finish( query );

    bson_print(query);

    int status1;
    status1 = mongo_run_command(mNoSQLConnection, "DB_NAME", query, b_result);
    if (MONGO_OK != status1 )
    {
    }
    else
    {
        /*command results*/
        bson_print(b_result);
    }

    bson_destroy( query );
    mongo_cursor_destroy( cursor );

}

有人可以帮助我搞清楚上面代码中的错误吗？

由于