PHP - Probably Easy Question About Operators

Hey people!

I've been setting a coding script for experience and this is my situation:

To buy a virtual flower, one needs to have 50 virtual coins.
So I first extract the number of coins the person has from the DB.
If the user doesn't have the sufficient number of coins, the BUY button will not be available and vice versa.

When the BUY button is clicked, I update the database, adding the flower to the user's inventory and subtracting 50 from the total number of coins the user has. This I do in that page itself using
if(isset($_POST['submit'])) 

Now, I need to know how I could check whether the user has at least 50 coins even if the button is available.
I hope that you could understand this.
I want to do it for validation purposes. Its to prevent the user spending the coins he has in another browser window and then returning to the visible button to click it.

I hope that I make sense. Thanks in advance!

Regards,
Thauwa

I'm trying to search the 'ad' column where 'ad' = 1 or 3

I'm having problems doing this.

Here is what I currently have, but it is not bringing back 'ad' where ='1' (for obvious reasons)
Quote

    $query = "SELECT * FROM users WHERE ad='3' AND state='$state1'";



Here is what I thought would work, but it displays every listing in my database when I do it this way.

Quote

    $query = "SELECT * FROM users WHERE ad='3' OR ad='1' AND state='$state1'";




Thank you in advance for your answers, google is not being so kind to me right now.

Hello Everybody   I usually work with C#, but I'm doing a website right now and have a question: I want a picture in my header and when I change the window size the image may not move.   My code so far:

#a1 { 
position: relative;
top:-175px; left:0px; width:50px; height:50px;
background-image:url(http://domain.png);
      background-repeat:no-repeat;}
</style>

Hope someone can answer this question easy

Wow, am I glad I found this forum!  I spent the past few hours trying to modify a PHP/mySQL script in order to test it. What this script does is basically look up a mySQL database (based on ip2nation) to find out what country and currency the IP address belongs to. This is the code sample:

Code: [Select]
$sql = 'SELECT  c.country, c.curr_code FROM  ip2nationcountries c, ip2nation i WHERE  i.ip < INET_ATON("24.24.24.24") AND c.code = i.country ORDER BY  i.ip DESC LIMIT 0,1';

        $countryName = $db->get_sql_row($sql);

I tested the code in PHPmyAdmin and it returns 2 rows:

country ------- curr_code (row names)
United States ------- USD (actual values)

So basically 2 variables, United States and USD. Now comes the problem, in order to test the script for several countries, I need to be able to "override" the result in the PHP script

I tried to do that by commenting out the part that returns the result from the mySQL query and modifying it with the following style, but I think I'm doing something wrong:

Code: [Select]
### $countryName = $db->get_sql_row($sql); ###

$countryName = "United States USD";

Is there any way that I can temporarily override the result returned by mySQL and "fake it" so to say? I understand the mySQL query returns 2 rows, so how would I go about overriding 2 rows?

I hope this makes sense ...you're all my last hope.

 

How can I use an include file that has a list of links in any directory at my website without breaking those links?

You can see it in action here...

The links in this directory work...

https://www.billelgin.com/primary-directory/

The links in this directory (being created from the same include file) do not work...

https://www.billelgin.com/primary-directory/subsection-one/

Obviously the problem is the include file is being called from different directories, so it's breaking the relative path links in the include file, but what can I do to fix it?

You can download the example directory structure here...

https://www.billelgin.com/EXAMPLE.zip

Alright, so I just started picking up PHP again and I have a pretty simple question. I have a html form that takes a string then writes it on another page. My problem is when I use quotations I'll get slashes in them on the page it writes the string on.

Is there a way to clean that stuff up?

I am very new to php and am trying to create a simple application that uploads a PDF file to a database. I have one field for the Volume Number and on file field for the PDF to be uploaded. My issue is i can't get the PDF to upload or insert the name of the pdf (eg volume1.pdf) into the data base.

I would also like to point out that I know i have a low post count, but i only seek help when i truly need it and have exhausted all other resources...

Here is what i have, please go easy on me this is my first round at php:
Code: [Select]
<?php
if(isset($_POST['submit'])){
$vol_num = $_POST['vol_num'];
$pdf = $_FILES['pdf']['name'];
$path = '../pdf/'.$_FILES['pdf']['name'];
move_uploaded_file($_FILES["pdf"]["tmp_name"], $path);
        mysql_query("INSERT INTO volumes set vol_num='$vol_num', vol_link='$pdf'") or die (mysql_error());
echo "<script>location.href='add_volume.php'</script>";
}
?>
what am i doing wrong here?

Thanks in advance

Hi guys!

I am trying to understand why the final value of $m equals 40 in the following code

Code: [Select]
<?php
$i = 29;
$j = 11;
$m = 10;

$j = ($j - 4) / 2;
$m += $j * 10;
echo "m = ".$m."<br>"; //Equals 40
?>

Can anyone explain me please? I feel very confused right now. 

I came across these pieces of code and have been trying to understand  this operator  ->
Or if it is a operator. I have searched and couldn't find explanations. In trying to learn I need to know what is is used for. Is it used only with classes?

$m->myMethod();

return  $this->x;

I have a query that is very messy.  I have tried using () to seperate everything and when I do it just all goes wrong.

here is the query



SELECT posts.*, users.*, countries.countryID, countries.country FROM posts 
INNER JOIN users ON users.userID = posts.postUserID INNER JOIN countries ON countries.countryID = users.userCountry WHERE posts.cityID = '".$row_rs_city['cityID']."'  AND posts.type = 'sightseeing' OR posts.cityID = '".$row_rs_city['cityID']."' AND posts.type = 'Inner city sightseeing' OR posts.cityID = '".$row_rs_city['cityID']."' AND posts.type = 'Outer city sightseeing'  ORDER BY posts.postID DESC

 

Is there a way of re-writing this so that it has brackets seperating everything and it will still work.  It works for the minute but re- writing posts.cityID = '".$row_rs_city['cityID']."' inbetween every OR just seems wrong.

Thanks for your help guys

Hi every one,

I just want to know what is the use of '<<' and '>>' operators in php

i'm trying to develop a deeper understanding of sessions, and I found this article on php.net regarding sessions with the following script;

<?php
    // Get the private context
    session_name('Private');
    session_start();
    $private_id = session_id();
    $b = $_SESSION['pr_key'];
    session_write_close();
   
    // Get the global context
    session_name('Global');
    session_id('TEST');
    session_start();
   
    $a = $_SESSION['key'];
    session_write_close();

    // Work & modify the global & private context (be ware of changing the global context!) 
?> 
<html>
    <body>
        <h1>Test 2: Global Count is: <?=++$a?></h1>
        <h1>Test 2: Your Count is: <?=++$b?></h1>
        <h1>Private ID is <?=$private_id?></h1>
        <h1>Gloabl ID is <?=session_id()?></h1>
        <pre>
        <?php print_r($_SESSION); ?> 
        </pre>
    </body>
</html>
<?php
    // Store it back
    session_name('Private');
    session_id($private_id);
    session_start();
    $_SESSION['pr_key'] = $b;
    session_write_close();

    session_name('Global');
    session_id('TEST');
    session_start();
    $_SESSION['key']=$a;
    session_write_close(); 
?> 

[EDIT BY danbrown AT php DOT net: Contains a bugfix provided by (lveillette AT silexmultimedia DOT com) on 19-NOV-09.]

I do not understand line 21 and 22.

<h1>Test 2: Global Count is:<?=++$a?></h1>

If I change this to;

        <h1>Test 2: Global Count is:<?php echo =++$a; ?></h1>
or
        <h1>Test 2: Global Count is:<?php =++$a ?></h1>

I would get a parse error, unexpected "=" in line 21.

Can anyone explain why this is?

* Why is it being echoed
* Why can I not use echo in this case
* Why does the code not start with <?php ?
* What does line 21 even mean? =++$a?       Thanks in advance guys!
Edited by empec, 13 July 2014 - 11:30 AM.

I'm trying to get an equation from a user that types it in the url, ex) 1+2+3. I can get the 1,2,3 fine, but the + operator is no longer in the string. Same with the * and / operators. Is there a way to keep them as a string using $_GET?

In php is there a way to shortcut logical operators... example:

Code: [Select]
if ($row['CustomerSaas'] == 'Yes' && ($row['CustomerSaasPaidStatus'] == 'Trial' || $row['CustomerSaasPaidStatus'] == 'Trial Ended')) {
to
Code: [Select]
if ($row['CustomerSaas'] == 'Yes' && ($row['CustomerSaasPaidStatus'] == 'Trial' || 'Trial Ended')) {

hi everyone   i keep seeing the following Comparison Operators: 

<>

i see it used in the following context:

if ($connection <> 'SSL')
    {
    $connection = 'NONSSL';
}

be grateful if somone would tell me what it means, i looked online but could not find the symbol   thanks