00 16,18,19,20,21 * * * mysql -h MY-DB-HOST.COM -u MY-DB-USERNAME -pMY-DB-PASSWORD -e "delete from hotaru_posts where post_id in ( select post_id from ( select post_id from hotaru_posts a group by post_title having count(post_title) > 1 ) b )" >> /tmp/cron_job.log

00 8,14,18,19,20,21,23 * * * /usr/local/bin/php /home/aikaforum/cata/public_html/cron_dup.php >> /cata/tmp/cron_dup.log

<?php
$username="xxxxxxx";
$password="xxxxxx";
$dbname="xxxxxx";
$dbhost="xxxxx.xxxxx.com";
$query="delete from hotaru_posts where post_id in ( select post_id from ( select post_id from hotaru_posts a group by post_title having count(post_title) > 1 ) b )";
mysql_connect($dbhost,$username,$password);
@mysql_select_db($dbname) or die(strftime('%c')." Unable to select database");
mysql_query($query);
mysql_close();
echo strftime('%c')." ok!";
?>

echo "your_SQL_statement" | mysql --skip-column-names -udbuser -pdbpassword yourdb >> yourlog.log

mysql -u username dbname -e "delete from posts" > foo
 cat foo
 (empty file)

00 16,18,19,20,21 * * * /usr/local/mysql/bin/mysql -h MY-DB-HOST.COM -u .....