Two identical formulas producing differing results - mysql

Question

I have a table of items and a table of categories. Each item is saved with it co-ordinates, latitude (lat) and longitude (lon), to allow users to search geographically.
When I do a search for items, those which have exactly the same lat and lon as the user, show in one query but not the other.
One query simply selects all items within a category (2), within a range (<1).
SELECT *, c.name as category, c.category_id as CATid,
( 3959 * acos( cos( radians(52.993252) )
* cos( radians( i.latitude ) )
* cos( radians( i.longitude ) - radians(-0.412470) )
+ sin( radians(52.993252) )
* sin( radians( i.latitude ) ) ) ) AS distance
from items i
join categories c on i.category=c.category_id
where i.category=2 group by i.item_id
HAVING distance < 1
order by distance
The other query selects all the categories and counts the number of items within each category, within the specified geographic range (<1)
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
HAVING distance < 2 ) AS howmanyCat,
( SELECT name FROM categories WHERE category_id = c.parent ) AS parname
FROM categories c ORDER BY category_id, parent
Strangely, if you change the search parameter for distance to 2 on the second query it finds it!
Any ideas?
Here is a fiddle to show what I mean

Answer 1

The second query is assigning the count() value as distance.
The first is assigning the arithmetic calculation as distance.
The first is doing what you want, and it is a clearer query.
EDIT:
I also note that the first query is aggregating by item_id. The second is not doing an explicit aggregation in the outer query, but it is choosing all categories. This is another difference between the versions.