public static function getSampleStandardNum($where) { self::initDB(); $sql = "select * from " . self::$table . " {$where}"; $query = self::$dbConn->query($sql); if ($query) { $ret = self::$dbConn->num_rows($query); return $ret; //成功, 返回列表数据 } else { self::$errCode = "003"; self::$errMsg = "444444444"; return false; //失败则设置错误码和错误信息, 返回false } }