jQueryUI Autocomplete - PHP SELECT values FROM multiple tables - php

Question

I am using jQueryUI autocomplete to search a mySQL database. I have this working for a single column from the database, but I want the autocomplete to search several columns at the same time.
e.g. Tables:
Companies Sectors
---------- ---------
company_id sector_id
company sector
So I want the autocomplete to search both the Companies.company AND Sectors.sector and provide autocomplete suggestions from both tables.
This is the php I have been using so far which does not return an error or data to the autocomplete:
<?php
$con=mysqli_connect(database_details);
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$q = strtolower($_GET["term"]);
$return = array();
$query = mysqli_query($con, "SELECT company FROM companies UNION SELECT sector FROM sectors AS data WHERE data LIKE '%$q%'");
if($query === FALSE) {
die(mysql_error());
}
while ($row = mysqli_fetch_array($query)) {
array_push($return,array('label'=>$row['data'],
'value'=>$row['data']
));
}
echo(json_encode($return));
mysqli_close($con);
?>
The JS is really simple:
<script>
$(document).ready(function search() {
$( "#search" ).autocomplete({
source: "php/search.php"
});
});
</script>
I am pretty new to this so please don't shoot me down, although this is likely a very simple error on my behalf :)
I have spent a lot of time (hours) trying to figure this out and not found any example code on stack overflow (or otherwise) that helps me complete this specific task.
Many thanks in anticipation

Answer 1

OK, so I been playing around with this a little more, it was an error with my mysqli_query as I had thought.
I had to change it to this to work:
SELECT company FROM companies WHERE company LIKE '%$q%' UNION SELECT sector FROM sectors WHERE sector LIKE '%$q%'
Most likely a very simple one for you experienced guys out there, but thanks for your help Tularis - testing the JSON return was what led me to this