<p>[ Log time: 1435555638.469 ] [ Expend time: 0.15747594833374 ] SELECT `item_id`, `type` FROM aws_topic_relation WHERE `topic_id` IN(12685) AND `type` = 'question'</p>

<p>[ Log time: 1435555638.6 ] [ Expend time: 0.024824142456055 ] SELECT `item_id`, `type` FROM aws_topic_relation WHERE `topic_id` IN(12685) AND `type` = 'article'</p>

<p>[ Log time: 1435555638.3101 ] [ Expend time: 1.4454081058502 ] SELECT question_id, best_answer FROM aws_question WHERE best_answer > 0 AND question_id IN (319551,319552,319553,319554,319555,319556,319557,319558,319559,319560,319561,319562,319563,319564,319565,319566,319567,319568,319569....(后面省略)

		        if (!$result = AWS_APP::cache()->get($cache_key))
        {
            if ($topic_relation = $this->query_all("SELECT item_id FROM " . $this->get_table('topic_relation') . " WHERE topic_id IN (" . implode(',', explode(',', $topic_ids)) . ") AND `type` = 'question'"))
            {
                foreach ($topic_relation AS $key => $val)
                {
                    $question_ids[$val['item_id']] = $val['item_id'];
                }

                unset($topic_relation);
            }
            else
            {
                return false;
            }

            if ($best_answers = $this->query_all("SELECT question_id, best_answer FROM " . $this->get_table('question') . " WHERE best_answer > 0 AND question_id IN (" . implode(',', $question_ids) . ") ORDER BY update_time DESC LIMIT " . $limit))
            {
                unset($question_ids);

                foreach ($best_answers AS $key => $val)
                {
                    $answer_ids[$val['best_answer']] = $val['best_answer'];
                    $question_ids[$val['question_id']] = $val['question_id'];
                }
            }
            else
            {
                return false;
            }