PHP script displaying a blank page - php

Question

This is my script and it's displaying a blank, I have no idea what the problem is. HELP!!!! #new to PHP
<?php include "connection.php";
// Get the ID from URL.
if(isset($_GET['id']));
$id = $_GET['id'];
$query="SELECT * FROM module WHERE id= '$id'";
$result= mysqli_query($m, $query);
while ($row = mysqli_fetch_array($result)){
$title=$row['title'];
$level=$row['level'];
$credits=$row['credits'];
$school=$row['school'];
echo $title. " " . $level. " " . $credits. "<br />";
}
?>
Error:
You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'WHERE id= 'Careers'' at line 1

Answer 1

One obvious problem here is that you've included an "end of statement" character being a semi-colon.
The semi-colon (if that isn't a typo), is doing just that, "ending" the statement.
if(isset($_GET['id']));
^ right there.
It should be a brace { for it instead and to read as:
if(isset($_GET['id'])){
and there should be a closing brace } for that conditional statement for it.
Sidenote: The semi-colon is considered a valid character in PHP, which won't throw you an error for it, should the GET array have a value.
However, you should check for errors for the rest of your code.
Add error reporting to the top of your file(s) right after your opening PHP tag
for example <?php error_reporting(E_ALL); ini_set('display_errors', 1); then the rest of your code, to see if it yields anything,
as well as or die(mysqli_error($m)) to mysqli_query().
While making sure you are indeed using the MySQLi_ API to connect with (different MySQL APIs do not intermix) and that the GET array has a value.
Here's a rewrite, and assuming a successful DB connection using the MySQLi_ API for it.
<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);
if(isset($_GET['id'])){
$id = $_GET['id'];
} else{
echo "ID is not set. You need to investigate it.";
exit; // This will stop your script, dead in its tracks.
}
$query="SELECT * FROM module WHERE id= '$id'";
$result= mysqli_query($m, $query) or die(mysqli_error($m));
while ($row = mysqli_fetch_array($result)){
$title=$row['title'];
$level=$row['level'];
$credits=$row['credits'];
$school=$row['school'];
echo $title. " " . $level. " " . $credits. "<br />";
}
References:
http://php.net/manual/en/function.mysqli-connect.php
http://php.net/manual/en/mysqli.error.php
Edit:
Taken from comments:
"this is my query, $query="SELECT id, title module WHERE id= '$id'"; – user5579012 38 mins ago"
Link to that comment...
That isn't what was posted in your original question.
You posted SELECT * FROM module WHERE id= '$id'.
You have a syntax error here, being a missing comma after title.
It should read as:
$query="SELECT id, title, module WHERE id= '$id'";
All columns need to be seperated by commas but not the last one being module here.

Answer 2

Ensure everything is ok. Echo errors if possible.
<?php include "connection.php";
// Get the ID from URL.
if(isset($_GET['id'])){
$id = $_GET['id'];
$query="SELECT * FROM module WHERE id= '$id'";
$result= mysqli_query($m, $query);
if($result){ //query is ok
if(mysqli_num_rows($result) > 0){//check if a record exists
while ($row = mysqli_fetch_array($result)){
$title=$row['title'];
$level=$row['level'];
$credits=$row['credits'];
$school=$row['school'];
echo $title. " " . $level. " " . $credits. "<br />";
}
}else{ //no result found
echo "no results found!";
}
}else{ //some error in querying
echo mysqli_error($m);
}
}
?>