Question

I am currently trying to access my database but receive the message

Undefined variable: link

My code is as follows:

define('DB_HOST', 'localhost');
define('DB_USER', 'root');
define('DB_PASS', 'penbird098');
define('DB_NAME', 'cmstest');

$link = @mysqli_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME) or die(mysqli_error($link));
mysqli_set_charset($link, 'utf8');

function getPosts(){

    $query = "SELECT * FROM post" or die($link);
    $result = mysqli_query($link, $query);
    $num = mysqli_num_rows($result);

    if($num > 0){

        while($row = mysqli_fetch_array($result, MYSQLI_ASSOC)){
            echo $row['Title'];
        }

    }
}  

getPosts();

What am I doing wrong? I have read the code and re-read it several times as well as looking around on Google and randomly trying different possibilities, but cant work out why. I’m guessing its something to do with not being able to pass a variable from outside a function into a function, but if I’m right, I don’t know how to do this or what the best way would be to do it, advice will be gratefully received.

Also I’m trying to use best practice with my code, so anything else which isn’t right would be good to know.

PS
the connection is in includes/connect
the function is in includes/functions
Calling the function is in index

Answer 1

Add the following line to your function:

global $link;

See this reference on using global variables in a function scope: http://php.net/manual/en/language.variables.scope.php

From the above reference:

This script will not produce any output because the echo statement
refers to a local version of the $a variable, and it has not been
assigned a value within this scope. You may notice that this is a
little bit different from the C language in that global variables in C
are automatically available to functions unless specifically
overridden by a local definition. This can cause some problems in that
people may inadvertently change a global variable. In PHP global
variables must be declared global inside a function if they are going
to be used in that function.