Okay I just tried this for admin logs and it works fine but I just used the simple truncate command in the query.
It was my test board so it got to be a pain adding rows back to the table for testing.
$sql = "TRUNCATE TABLE `ubbt_ADMIN_LOG`";
$dbh->do_query($sql);
$body = <<<EOF
SQL to clear logs
EOF;
The part about sql to clear logs was just to indicate to me that that island did appear on the forum.