Select row before&after certain value?

NSH

The subject doesn't seem right.. but my brain is hurting right now.

Let me explain my issue:
I am trying to make a Comic Display script, complete with archiving features, next/previous buttons, etc.

I have read the many threads and tutorials on next/prev.
I have made my own version of that code by tweaking some froma tutorial.... however I have a problem...

The code works perfect for next/previous even after adding new comics.... that's not the issue... The issue is that say someone views a comic after clicking previous a few times, so the offset is equal to 3... well you can copy the link of course and come back later by that url AS LONG as a new comic isn't added... if so you get the wrong image...

I'm not sure if I have explained very well, but I have been trying to wrap my brain around a concept on how to resolve my issue.

I would like to uyse dates as my variable, which doesn't seem to be a problem...

The only thing I can come up with is if there is a way to find data in mysql and then search the row before and after it... this will give you next/prev data....

There must be an easier way... but I can't think of it.
(www.penny-arcade.com has basically what I need)
I have tried searching the net, but I can't find many scripts that do what I want so I can disect them and see how they tick...

I only ask for help cause I am going nuts....

Thanks in advance!!

NSH

I know there is a guru out there who has all the answers for PHP 🙂

Where is weedpacket when ya need him....

I have tried making progress, but honestly I can't think of a single way to do what I need to... it has to be more simple than I am making it..I however, never claimed to be intelligent....

I appreciate anyone who responds.... even if it's to call me names...

Thanks,
NSH

The_Chancer

Have you got an auto increment line in yoru database.. if so just pull out the ID and either add one or take one away from it...

Think that could be what you are after....

Failing that use timestamp and look at the next and previous closest times...

NSH

Timestamp won't work because there may be days without a new comic.

Id won't work(tried that) because if one is added and for some reason deleted it scews everything... Ie

ID
15
16
17

16 is removed and 17-1 will show no result...

Penny-arcades comic(as well as pvponline.com) does what i need, but getting that code isn't going to happen 🙂

I appreciate the help though.

If I wasn't worried about someone removing a comic i don't think i would mind the auto increment idea....

marque

referencing by the auto incremended ID will work, just not the way you are thinking of.

True 17 - 1 will return no result and a crap looking or eronomus page.

Rather than trying to write multiple code, etc use this:

mysql_fetch_row

Retrieves the next row of a result set. When used after mysql_store_result(), mysql_fetch_row() returns NULL when there are no more rows to retrieve. When used after mysql_use_result(), mysql_fetch_row() returns NULL when there are no more rows to retrieve or if an error occurred.

Go here for more info

http://www.mysql.com/doc/en/mysql_fetch_row.html

NSH

I am able to retrieve the next row easily.. however I can't seem to retrieve the previous row.... I am searching these forums for some more reading as well as mysql and php.net sites...

I appreciate the help, maybe I am just not seeing the concept...

cmburns69

Back to the auto increment idea, instead of searching for a single record, why not get the previous 5:

In the example, the table has 5 IDs: 12, 13, 15, 17 and 18. The user is displaying the page with ID 15. The previous and next links should point to 13 and 17 respectively. The following code is a little more complex than "$current_page minus 1"

<?
$current_page = "15";
$r = mysql_query("select id from table where id < $current_page order by id desc limit 1");
$previous_page = mysql_result($r,0);
// Always remember to do cleanup!
mysql_free($r);

$r = mysql_query("select id from table where id > $current_page order by id limit 1");
$next_page = mysql_result($r,0);
// Always remember to do cleanup!
mysql_free($r);
?>

This code should work whether you're using an auto increment, date or any type of incrementing value.

The limit clauses in the SQL are important, because with a large table every result is sent to the PHP script, even if only 1 row is important.

Tom Brown
Netnexus: Where gamers play
www.netnexus.com

NSH

I was on the right track earlier and I had almost the same code written.. I wasn't sure how the hell to use mysql_result(thought it had to be with mysql_row_seek)

All I have to say is, your code works perfectly.
You are a life savior, literally... I was about to bang my head on the desk until I passed out or died....

Thank you so very much...... I am eternally greatful