Search by alias without showing the alias - mysql

Question

I have a table of categories and a table of items.
Each item has latitude and longitude to allow me to search by distance.
What I want to do is show each category and how many items are in that category, within a distance chosen.
E.g. Show all TVs in Electronics category within 1 mile of my own latitude and longitude.
Here's what I'm trying but I cannot have two columns within an alias, obviously, and am wondering if there is a better way to do this?
Here is a SQL fiddle
Here's the query:
SELECT *, ( SELECT count(*),( 3959 * acos( cos( radians(52.993252) )
* cos( radians( latitude ) )
* cos( radians( longitude ) - radians(-0.412470) )
+ sin( radians(52.993252) )
* sin( radians( latitude ) ) ) ) AS distance
FROM items
WHERE category = category_id group by item_id
HAVING distance < 1 ) AS howmanyCat,
( SELECT name FROM categories WHERE category_id = c.parent ) AS parname
FROM categories c ORDER BY category_id, parent

Answer 1

First, start with the distance calculation for each item, then join in the category information and aggregate and filter
select c.*, count(i.item_id) as numitems
from category c left outer join
(SELECT i.*, ( 3959 * acos( cos( radians(52.993252) ) * cos( radians( latitude ) )
* cos( radians( longitude ) - radians(-0.412470) ) + sin( radians(52.993252) )
* sin( radians( latitude ) ) )
) AS distance
FROM items i
) i
on c.category_id = i.category_id and distance < 1
group by category_id;

Answer 2

Is this what you're looking for:
SELECT categories.name, count(items.item_id) as cnt
FROM items
JOIN categories
ON categories.category_id=items.category
WHERE ( 3959 * acos( cos( radians(52.993252) )
* cos( radians( latitude ) )
* cos( radians( longitude ) - radians(-0.412470) )
+ sin( radians(52.993252) )
* sin( radians( latitude ) ) ) ) < 1
GROUP BY categories.category_id;
this gives:
Tvs | 1

Answer 3

You can put the expression for computing the distance inside a nested SELECT, and then join the results to the categories table, like this:
SELECT COUNT(*), cc.name FROM (
SELECT
i.item_id
, c.category_id
, ( 3959 * acos( cos( radians(52.993252) )
* cos( radians( latitude ) )
* cos( radians( longitude ) - radians(-0.412470) )
+ sin( radians(52.993252) )
* sin( radians( latitude ) ) ) ) AS distance
FROM items i
JOIN categories c ON c.category_id = i.category
) raw
JOIN categories cc ON raw.category_id = cc.category_id AND raw.distance < 1
GROUP BY cc.name
The nested query pairs up items and categories, and adds the calculated distance column. The outer query then filters the rows by distance, and groups them by category to produce the desired output:
COUNT(*) NAME
-------- ----
1 TVs
Demo on sqlfiddle.