SQL, SELECT items which specific date is not booked

Question

I have items list. Every single item may be booked for specific date, eg. 2013-01-03 00:00:00, 2013-06-13 00:00:00 etc. I have to filter items in way that shows available items for choosen date. If item have only single reservation there is no problem, but I don't know hot to construct query if item have a few reservations

cms_items

[id:int, name:varchar, category:int]

cms_items_reservations

[id:int,item_id:int,reservation_date:timestamp]

I use CodeIgniter and I created something like this:

    $this->db->
            select('DISTINCT(item.item_id), item.name, item.category', false)->
            from('cms_items_reservations AS rs')->
            join('cms_items AS item', 'item.id = rs.item_id', 'right')->
            where('item.category', $regionId)->
            where('DATE_FORMAT(rs.reservation_date, "%Y-%m-%d") <>', $date)->
            where('rs.item_id = item.id');

If item is reserved for 2013-06-13 and 2013-06-14 and I'm looking for items available for 2013-06-13 it's still returned with this query.

I don't want. I'm looking for most simpliest way. Any advices?

Answer 1

You can use a simple subquery like

SELECT * FROM cms_items WHERE id NOT IN (
SELECT item_id FROM cms_items_reservations WHERE 
DATE_FORMAT(reservation_date, "%Y-%m-%d") ='2013-06-13')

$this->db->query("SELECT * FROM cms_items WHERE id NOT IN (
SELECT item_id FROM cms_items_reservations WHERE 
DATE_FORMAT(reservation_date, '%Y-%m-%d') ='".$date."')");