it works as long you have no comments saved for your news.. Then you must delete the corresponding comments also.
You can do it if you execute following 2 SQL-Queries after each other.:
replace xxxx with your TABLE_PREFIX
>>first execute
DELETE `t1`, `t2` FROM `xxxx_mod_news_posts` AS `t1`
INNER JOIN `xxxx_mod_news_comments` AS `t2`
WHERE `t1`.`post_id` = `t2`.`post_id` AND `t1`.`posted_when` < UNIX_TIMESTAMP( '2005-03-27 03:00:00' )
>>second execute
DELETE FROM `xxxx_mod_news_posts`
WHERE `posted_when` < UNIX_TIMESTAMP( '2005-03-27 03:00:00' )
First query will delete all posts with all attached comments
Second query will delete all other posts without comments.
The order of executing queries is very important!
The SQL-function
UNIX_TIMESTAMP makes it easy to insert the timestamp. The format is: ( 'yyyy-mm-dd hh:mm:ss' )