Paging with PHP/MySQL?

[Leviathan]

Say, anyone familiar with PHP and the MySQL API? I've got a lil' problem on my hands that I can't remember how to do.

Basically, it's paging. And I'm trying to retrieve a string value from a row in a table whose primary is one greater than the record being viewed.

Sooo if anyone can direct me to some handy pagination code, that'd be great!

 

[Tsutarja]

Gonna move this into its own thread since it appears to be a larger issue at hand, and since the DCC thread is mainly for small talk/rolling discussion. :)

 

[Petie]

Is there no chance for gaps in your data? Are you always retrieving a single value that is one higher (or lower) than the current one? This is fairly simple then:

Assuming you have the current ID stored in $id (and you're properly sanitized it with something like intval() when setting it):

SELECT string_col FROM table WHERE id = $id + 1;

If you don't know that $id + 1 exists, you can do:

SELECT string_col FROM table WHERE id > $id ORDER BY id LIMIT 1;

And the same applies in reverse if you want to go backwards.

I feel like this is too simple and I'm missing something though. Let me know and I can provide more detailed code samples, especially if you tell me how you're interfacing with the database (the old mysql commands, mysqli, pdo, etc.).

 

[Petie]

LIMIT and OFFSET are used in my more specific examples but the OP seemed to state that only a single row needed to be returned so it's not "paging" in the traditional sense; it sounds more like browsing through individual items in a collection which is conceptually a bit different.

 

[Touched]

In more general terms, you can also refer to the LIMIT clause which is very useful for simple paginations.

Ah W3Schools my fickle friend, we meet again.