/** * 学生考试的paper_id */ public function get_student_exam_paper($uid, $exam_id) { if (empty(self::$_paper_ids[$uid][$exam_id])) { self::$_paper_ids = array(); $sql = "SELECT paper_id FROM rd_exam_test_paper\n\t WHERE exam_id={$exam_id} AND uid={$uid} AND etp_flag=2"; self::$_paper_ids[$uid][$exam_id] = self::$_db->fetchOne($sql); } return self::$_paper_ids[$uid][$exam_id]; }