PHP and mysqli to modify CSS

Question

I was experimenting if I could use a mySQL database to store CSS settings. I set up a simple database "colors" with one table "color" that had simple structure tag and color columns. In that, one row is h1 => red.

<?php
//function to dynamically change CSS

    $tag = 'h1';
    $q = "SELECT * FROM `colors` WHERE `tag`='" . $tag . "'" ;
    echo $q . "<br>";
    $query = mysqli_query($link, $q);
    if ($row = mysqli_fetch_assoc($query))
    {
        echo $row['color'];
    } else
    {
        echo "error - no such tag";
    }
?>

When I tried to convert to a function, the code does not work at all.

<?php
//function to dynamically change CSS
function getCSS($tag)
{
    $tag = 'h1';
    $q = "SELECT * FROM `colors` WHERE `tag`='" . $tag . "'" ;
    echo $q . "<br>";
    $query = mysqli_query($link, $q);
    if ($row = mysqli_fetch_assoc($query))
    {
        echo $row['color'];
    } else
    {
        echo "error - no such tag";
    }
}
getCSS('h1');
?>

Help please?

remove $tag = 'h1' inside function body

mitkosoft
– mitkosoft

2016-02-24 13:44:32 +00:00
Commented Feb 24, 2016 at 13:44 — mitkosoft
– mitkosoft, Commented Feb 24, 2016 at 13:44
Please print your output or error.

Hiren Rathod
– Hiren Rathod

2016-02-24 13:48:51 +00:00
Commented Feb 24, 2016 at 13:48 — Hiren Rathod
– Hiren Rathod, Commented Feb 24, 2016 at 13:48

snitch182 · Accepted Answer · 2016-02-24 13:48:00Z

1

My guess is that in

$query = mysqli_query($link, $q);

$link goes out of scope and is empty. You should pass it to the function as well.

For the record: using $tag without escaping could be an sql injection attack possibility.

answered Feb 24, 2016 at 13:48

snitch182

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2 Comments

PAUL CLEGG Over a year ago

thank you. With regard to the SQL injection, I was just experimenting so not live. Appreciate the advice though.

snitch182 Over a year ago

Thats what i thought but on a site like this where everybody is learning ... functions get rewrapped a couple of times in the future ... and the lib goes live and voila... i completely stopped doing it. I recommend doing the same.

chenyb999 · Accepted Answer · 2016-02-24 13:48:37Z

0

in function, there is no $link, you shoud define it as a global variable.

answered Feb 24, 2016 at 13:48

chenyb999

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Comments

puppyFlo · Accepted Answer · 2016-02-24 13:50:39Z

0

At the start of your function add a reference to your global DB link:

function getCSS($tag) {
    global $link;
    ...

answered Feb 24, 2016 at 13:50

puppyFlo

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1 Comment

PAUL CLEGG Over a year ago

thanks a lot. All responsive point to he same problem. I do appreciate your time.

Marin N. · Accepted Answer · 2016-02-24 15:05:28Z

0

This should work:

<?php

$link = mysqli_connect('server_host', 'user', 'password', 'database') OR die('Could not connect because: '.mysqli_connect_error());

//function to dynamically change CSS
function getCSS($link, $tag){

$q = 'SELECT * FROM colors WHERE tag = "' . $tag . '"' ;
$r = mysqli_query($link, $q);

if(mysqli_num_rows($r)>0){ // check if there are results

    while($row = mysqli_fetch_assoc($r)){
    //echo '<pre>';      
    //print_r($row);            // print the result array for debugging
    //echo '</pre>';

    echo $row['color'] . '<br />';

    }

    return $row;

} else {  // if no result is found

    echo 'No such tag';

}

}
// test it:
echo '<br />if tag is h1<br />';
getCSS($link, 'h1');

echo '<br />if tag is h2<br />';
getCSS($link, 'h2');

?>

edited Feb 24, 2016 at 15:05

answered Feb 24, 2016 at 14:42

Marin N.

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