SQL syntax error edit post - php

Question

getting :
You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use
near 's Creed III', description='The plot is set in a fictional
history of real ' at line 2
when trying to edit posts on a database.
heres my display and edit php:
$result = mysql_query("SELECT * FROM gallery");
while ($row = mysql_fetch_array( $result )){
// while looping thru each record…
// output each field anyway you like
$title = $row['title'] ;
$description = $row['description'];
$year = $row['year'];
$rating = $row['rating'];
$genre = $row['genre'];
$filename = $row['filename'];
$imageid = $row['imageid'];
include '../modules/edit_display.html';
}
// STEP 2: IF Update button is pressed , THEN UPDATE DB with the changes posted
if(isset($_POST['submit'])){
$thisTitle = $_POST['title'];
$thisDescription = $_POST['description'];
$thisYear = $POST['year'];
$thisRating = $POST['rating'];
$thisGenre = $POST['genre'];
$thisNewFilename = basename($_FILES['file']['name']);
$thisOneToEdit = $_POST['imageid'];
$thisfilename = $_POST['filename'];
if ($thisNewFilename == ""){
$thisNewFilename = $thisfilename ;
} else {
uploadImage();
createThumb($thisNewFilename , 120, "../uploads/thumbs120/");
}
$sql = "UPDATE gallery SET
title='$thisTitle',
description='$thisDescription',
year='$thisYear',
rating='$thisRating',
genre='$thisGenre',
filename='$thisNewFilename'
WHERE
imageid= $thisOneToEdit";
$result = mysql_query($sql) or die (mysql_error());
}

Answer 1

You're suffering from an imminent dose of SQL Injection due to using a dangerous user input model.
When you type "Assassin's Creed III" in the title field, that gets placed in single quotes in the UPDATE statement in your code (via the $_POST['title'] variable):
'Assassin's Creed III'
The problem there is that MySQL sees it as 'Assassin', followed by s Creed III'. It doesn't know what to do with the latter.
Of course, this becomes a HUGE problem if someone types in valid SQL at that point, but not what you expected. Have a look at How can I prevent SQL injection in PHP? or any of several other advices on avoiding SQL Injection.

Answer 2

i have seen you are adding ' into database so you need to escape it using addslashes()
addslashes($thisTitle)

Answer 3

You have syntax error here. Use $_POST instead of $POST.
Replace
$thisYear = $POST['year'];
$thisRating = $POST['rating'];
$thisGenre = $POST['genre'];
With
$thisYear = $_POST['year'];
$thisRating = $_POST['rating'];
$thisGenre = $_POST['genre'];

Answer 4

you need to escape your input like
$thisDescription = mysql_real_escape_string($_POST['description']);
do this for all input that contains quotation marks etc..
NOTE: mysql will soon be gone so its advised to write new code using mysqli instead

Answer 5

You have alot of issues in your script.
You're trying to add ' character to database, you need to escape it properly with addslashes.
You're vulnerable to SQL Injection. Escape it properly with mysql_real_escape_string, or even better, use PDO.
Third, it is $_POST, not $POST. You're using it wrong in some areas.
Add quotes to $thisOneToEdit in query.
The error is causing because you're trying to add Assasin's Creed III string to database. The single quote breaks your query and creates a syntax error.

Answer 6

Do a addslashes() on the values that might contain single or double quotes like below before using them in query
$thisTitle = addslashes($_POST['title']);