Good OOP programming

Anon

Is there anybody who knows a good site about OO Programming?

In fact, I am wondering if it's better to write a function which retrieves information by a query and having to implement 3 different functions (and 3 queries) or is it better to code the query all in one?

like in a table with visitors: first name, last name, email. you need the three fields (sometimes together, sometimes alone). what would you do?

thx!

Anon

About the three fields,

In your example it is better to use one function that allways retreives all three fields together.
There will be no noticable speed improvement in fetching just one field.

Anon

Sometimes together sometimes alone.

Well, just get all the information in a database and extract only what is needed, I have a position column in one of my tables for ordering the data, its not displayed though :-)

Anon

yep, but how do you return the fields? yet again in an array? not that helpfull is it?

I would think of a function so that I can say in my script

$1stname = get_firstname($cookie_id);

You would suggest something like

$visitor = get_allinformation($cookie_id); where $visitor[1stname] contains the needed 1stname?

Anon

Regarding PHP OOP Tutorials :

http://www.php.net/manual/language.oop.php
http://phpbuilder.com/columns/rod19990601.php3
http://devshed.com/Server_Side/PHP/BackToClass/
http://devshed.com/Server_Side/PHP/Class/
http://zend.com/zend/tut/class-intro.php

Anon

Yup.

It doesn't matter wether I:
- retreive an array from the database, get my var from it, and return the var.
or
- retreive an array from the database, return the array, and pick my var from it.

So in the end it saves you writing a few functions. Which saves you some work lateron if you change your database setup or even your databasetype,
plus it makes your source a lot clearer.

Anon

yep, but how do you return the fields? yet
again in an array? not that helpfull is it?

Actually for good OOP programming you would use an object.

$1stname = get_firstname($cookie_id);
You would suggest something like
$visitor = get_allinformation($cookie_id);
where $visitor[1stname] contains the needed
1stname?

Instead, you would use something like this:

class Visitor
{
   var $FirstName;
   var $LastName;
   var $Email;
}

function getVisitor($cookie_id)
{
   // query your database and get your values
   // then create your object and populate it
   $retval = new Visitor;
   $retval->FirstName = [your db value];
   $retval->LastName = [your db value];
   $retval->Email = [your db value];
   return $retval;
}

Then in your code:

$thisUser = getVisitor($cookie_id);
echo $thisUser->FirstName;

Abd if you get even more into OOP you would actually define accessor methods instead of using public variables. In this case that may be overkill but is generally good OO practice.

G'luck,
Jack