[thelist] SQL: Deleting every row over 30

[Lauri Vain]

Hi there,

We're doing a classified system and for each item category we have, what
the project manager calls "discussion pages". It basically operates in a
simple 'guestbook style' with the exception that only 30 newest posts
will be kept in the database (for each category). Older posts will be
deleted altogether.

Obviously, I can't do
"DELETE FROM as_discussion WHERE parent='7' LIMIT 30,5" (You can't use
two numbers in LIMIT in case of a DELETE)

So, what would be the best way to delete every row over 30 from the
database? Any good suggestions?

Thanks in advance!


For those interested, the DB layout:
--------- DUMP ---------
CREATE TABLE as_discussion (
  id INT(11) NOT NULL auto_increment,	/* Unique ID */
  parent INT(11),					/* Parent
category */
  name text,					/* Post author */
  email text,					/* E-mail of poster */
  title varchar(200) default NULL,		/* Post title */
  body text,					/* Body text */
  dtime datetime default NULL,		/* Time */
  PRIMARY KEY (id),
  UNIQUE KEY id(id)
) TYPE=MyISAM;
--------- DUMP ---------

Yours,
Lauri
--
Tharapita Creations
[dynamic web applications]
lauri.vain at tharapita.com
Mobile: +372 53 410 610