MYSQL union PHP select into one result column - php

Question

Ok, there comes a point where staring at SQL is the only option when Googling has you cross eyed. I can't quite get my head around this. What I'm trying to do, is simply use 1 query to search multiple tables at once and return what it finds. I think I need to just do separate queries for this, but wanted to see if there is a better way.
So, for example, there is a categories table, and a users table. If the user searches for "jo", it might find "jobs" in the categories table, but it should also find "joe" in the users table. These are displayed in a <ul><li> html style with fixed lengths. Is there a way with one query? Ideally if "jobs" is found in the category table, that would end the record and the next record would contain "joe" from the users table (provided that the "jo" didn't have multiple categories from the category table.
I've played around with UNION SELECT, but am not sure if it can perform in this fashion or not. I might be able to get a result back from the query, but since the tables have more than 1 field name that is being searched on, I need to be able to return the result based on where it's from.
For example, something like:
SELECT cat_name as result FROM categories WHERE cat_name LIKE '%$name%'
UNION (SELECT firstname as result, lastname as result, username as result WHERE
firstname LIKE '%$name%' OR lastname LIKE '%$name%' OR username LIKE '%$name%' LIMIT 10
<?php echo $row['result']; ?>
Do you think it needs multiple queries?

Answer 1

I don't see that there is any harm in using multiple queries and using echo to display the results separately as to not confuse (so you know where to results are coming from).
Something like this wont burden your script in anyway and makes it easier to read.
<?php
$con=mysqli_connect("example.com","peter","abc123","my_db");
// Check connection
if (mysqli_connect_errno()) {
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$sql = "SELECT cat_name FROM categories WHERE cat_name LIKE '%$name%';";
$result = mysqli_query($con,$sql);
echo "<h1>Category Matches</h1>"
echo "<ul>";
while($row = mysqli_fetch_array($result)) {
echo "<li>" . $row['cat_name'] . "</li>";
}
echo "</ul>";
$sql2 = "SELECT * FROM users WHERE first_name LIKE '%$name%';";
$result2 = mysqli_query($con,$sql);
echo "<h1>User Matches</h1>"
echo "<ul>";
while($row = mysqli_fetch_array($result2)) {
echo "<li>" . $row['first_name'] . "</li>";
}
echo "</ul>";
mysqli_close($con);
?>