[Resolved] Delete from DB if more than X entries

Tad

I'm still researching all of this... but ah, I was wondering if anyone had any tips on doing something like this. I think I could probably run a cron job, but really, I know almost nothing about those.

I have this tagboard and what I'd like to do is automatically delete posts if there are more than 15 in the DB. So only 15 messages can exist in the DB at any given time.

Here's my insert query (tagid automatically increments)...

$DB->query("INSERT INTO tagboard (tagid, submitted, name, uid, submitdate, message ipaddress) 
	VALUES ('','$submitted','$name','$uid','".time()."', '$message', '$ipaddress')");

And that works just fine. Is it possible to run a delete query right after the insert though in order to remove the older entries so that only 15 remain in the DB? I've been trying to do this, but can't seem to get it to work. Any help would be awesome. Thanks. 🙂

kcgame

You might want to add a if loop to check and delete the oldest post if it exceeds 15 in db before inserting. Something like:

SELECT COUNT(tagid) FROM table WHERE CONDITIONS
Put COUNT(tagid) into an array for example, count_array[].

Then:

If (Count_array[0]>=15){
DELETE * FROM table WHERE CONDITIONS
//delete the oldest post
}
//INSERT QUERY here

Hope it helps.
There might be a query to do all in one thou...not too sure about that one..

Tad

Yeah. :/ I've been trying something like that. I was pulling the last mysql_insert_id() value after my insert and then trying to delete entries based on that, but I still can't get it to work. I think I'm Math impaired or something, lol. x_x So.. I still haven't solved this yet.

EDIT: Got it! At 3 am no less... lol.

I used a select query, got the num rows from that, matched that up with how many I wanted to be viewable, then used the difference of that number and my total in order to add a limit to my delete query. Hurray. Thanks for your help.