A few difficult (for me at least) PHP questions

Anonymous posted this at 14:56 — 4th December 2001.

Joined: Jan 1970

Hi everyone. I've been working on a PHP and MySQL system to run my website, but have run into a brick wall with a few matters.

1. I have a seperate "products" and "articles" tables. When a user requests an article using a URL such as "articles.php?a=1" (where 'a' is the article ID). In the articles table, there is a "Product_ID" field which references that article to the relevant product, and a "Article_Type" which says whether the article is a review, preview or feature. What I need is for the page to search for products of the same ID, and a particular "Article_Type". From this result, I need to use an if-else statement to either display one of two images. The if-else statement shouldn't be too difficult, but how would I write to code to display one image if an article was found (with a hyperlink on the image to the relevant article, and another if it wasn't.

2. How can I assign a variable if it was not given in the URL. For example, if the URL is default.php?s=1 no new variable is assigned, but if only default.php is given, a script automatically assigns s=1.

I thought this would work, but for some reason it hasn't:

<?php
 if(s=\"\") {
s=1;
}
?>

What am I doing wrong?

3. Finally, on my site, there is an area for volunteers to edit products, I used the following code to insert the values into the database, but it never works, failing, and showing the failed error defined in "if (!mysql_query($sql))"

<?php
$sql = \"UPDATE TABLE products SET 
Product_Name = '$newProduct_Name',
Product_Type = '$newProduct_Type',
Min_Specs    = '$newMin_Specs',
Rec_Specs    = '$newRec_Specs',
Publisher    = '$newPublisher',
Developer    = '$newDeveloper',
Multiplayer  = '$newMultiplayer',
Graphics     = '$newGraphics',
Release_Date = '$newRelease_Date',
Price        = '$newPrice'
WHERE Product_ID=$id\";

if (!mysql_query($sql)) {
 echo(\"2. A database error occurred in processing your \".
 \"submission. If this error persists, please \".
 \"contact <a href="mailto:anthony@epigamer.com" class="bb-email">anthony@epigamer.com</a>.\");
}
?>

Thanks everyone, any help will be greatly appreciated as usual.

Wil posted this at 15:21 — 4th December 2001.

They have: 601 posts

Joined: Nov 2001

A lot more of your script would be very useful in helping you with your problems.

You know this variable you are trying to define? Does the variable get defined from a database? A much better way to write that would be:

if (!$s) 
{
 $s = 1;
}

'
Please note that I come from a Perl background and not a PHP one, although both language do share common properties.

Surely you have to state what kind of data structure 's' is? Is it a scalar, array, hash, monkey, elephant?

For your second question, hmm. I think I'll need more information again. How are you preparing and executing this? A few notes, however, the line:

"$sql = "UPDATE TABLE products SET"

should be replaced with:

$sql = "UPDATE products SET

'
You don't need TABLE there. In fact, that could actually be your error.

Put your last statement on a seperate line. It looks cleaner, and you can also enclose that with single quotation marks too.

...
WHERE
Product_ID = '$id'

Cheers

- wil

Mark Hensler posted this at 17:11 — 4th December 2001.

He has: 4,048 posts

Joined: Aug 2000

By default, all variables are variant. You can, however, type cast them. But you'll rarely ever see anyone do that in PHP. Examples:

<?php
// make a dummy var
$tmp= \"1234\";

// let's type cast
$myString = (string) $tmp;
$myInt = (int) $tmp;
$myBool = (bool) $tmp;

// let's settype()
$myString = settype($tmp, \"string\");
$myInt = settype($tmp, \"int\");
$myBool = settype($tmp, \"bool\");
?>

PHP Docs: type-casting, type-juggling, settype()

Mark Hensler
If there is no answer on Google, then there is no question.

Wil posted this at 18:27 — 4th December 2001.

They have: 601 posts

Joined: Nov 2001

Hi Mark

I wasn't claiming that all variables weren't variants, what I was saying was that he hadn't of defined what kind of data strcuture 's' is. Is it a scalar, array, hash, syscall etc.

- wil