我写的插件，我有自定义表。我正在尝试从此自定义表的最后5行中随机访问一行。

"SELECT * FROM $table_name WHERE id > MAX(id)-5 AND id < MAX(id)+1 ORDER BY `time` DESC LIMIT 1"; 

UPDATEproblem排序为；

$ofset = rand(0, 4);
 $read_link_data = "SELECT * FROM $table_name ORDER BY `time` DESC LIMIT $ofset,1";