试试这个:

删除发件人WHERE id 不在 (选择 * 从 (选择 ID发件人ORDER BY timestamp desc limit 0, 15)作为 t);

This is probably an easy one... how can I achieve what i want with this query:

delete from posts where id not in
(SELECT id FROM posts order by timestamp desc limit 0, 15)

so, to put it in a nutshell, I want to delete every post that isn't on the latest 15.

When I try that query, I get that

MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery

EDIT

mySQL Server version: 5.5.8
mySQL Client version: mysqlnd 5.0.7-dev - 091210 - $Revision: 304625 $

Error: #1235 - This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'

Try this:

DELETE 
FROM posts 
WHERE id not in (
      SELECT * FROM (
            SELECT id 
            FROM posts 
            ORDER BY timestamp desc limit 0, 15
      ) 
      as t);