proper sytax/ methof for UPDATE mysqli_query() - php

Question

Okay I have this syntax for an UPDATE to a table in mysql inside a php script:
mysqli_query($con,"UPDATE ted SET description=$line[5]
WHERE speaker='$speaker' AND event='$event'");
Is there somehting wrong with it? it runs properly in my scriipt (no error's) however no updates are made even though: it is called multiple times (and has lines which match the WHERE condition) heres the entire script
<?php
$contents = file_get_contents('ted_csv.txt');
$con=mysqli_connect("localhost","root","admin","Media2net");
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$result = mysqli_query($con,"SELECT * FROM ted");
$i=0;
while($row = mysqli_fetch_array($result))
{
$speaker =$row['speaker'];
$event =$row['event'];
$pattern2 = preg_quote($speaker, '/');
$pattern1 = preg_quote($event, '/');
$pattern1 = "/^.*$pattern1.*\$/m";
$pattern2 = "/^.*$pattern2.*\$/m";
if(preg_match_all($pattern1, $contents, $matches)){
$submatch = implode("\n", $matches[0]);
if (preg_match_all($pattern2, $submatch, $better)){
echo "got match" . $i . "\n";
$line =str_getcsv( $better[0][0] );
$a_bool = mysqli_query($con,"UPDATE ted SET description=$line[5]
WHERE speaker='$speaker' AND event='$event'");
if ($a_bool){
echo "got match" . $i . "\n";
}else{
echo "query unsuccesful for match" . $i . "\n";
}
}
}
$i++;
}//end of while loop results
mysqli_close($con);
?>
As you can see a match should be available as same string's $speaker and $event were pulled from table ted
So clearly there's something wrong with my syntax as for each query $a_bool is false resulting in echo "query unsuccessful for match" . $i . "\n" being called for each query . Any explanation of what I have done wrong would be greatly appreciated!

Answer 1

SET description=$line[5] should be in quotes
like
mysqli_query($con,"UPDATE ted SET description='{$line[5]}'
WHERE speaker='$speaker' AND event='$event'");