I'm trying to create a caravan booking system for work. However i have run into alot of problems with my queries on my reserve table.

I want, when making a booking to be able to press a button and a list of available caravan pitches is displayed for those dates. There are 12 avaliable sites.

Can anyone give me some guidance?

Can you post the statements you already have? someone may be able to point you in the right direction.

For example, the caravan park has 12 sites. Each site can be booked for a number of days throughout the year e.g. a weekend.

What i want to be able to do is provide a booking system to enable this. But at the moment i'm experiencing double bookings. The query doesn't seem to recognise the logic of the situation.

An example is: I want to book a caravan into site 5 for a weekend fri-sun, once i press the button return avaiable sites, i want it to return all sites that have no bookings on that site between those dates. I i create a query showing me the sites that are not avaible it works ok, but i want it to return me a list of the sites that ARE avaiable on those dates. I seem to be unable to invert the code.

Here's the SQL for the query that returns the sites that are not available. I want to invert this:

SELECT DISTINCT SITE.[Site#], SITE.Description
FROM SITE LEFT JOIN RESERVE ON SITE.[Site#] = RESERVE.[Site#]
GROUP BY SITE.[Site#], SITE.Description, RESERVE.Arr_date, RESERVE.Dept_date, RESERVE.[Site#]
HAVING (((RESERVE.Arr_date) Not Between [Forms]![SITE_RESERVATIONS]![Arr_date] And [Forms]![SITE_RESERVATIONS]![Dept_date] And (RESERVE.Arr_date)>Now())) OR (((RESERVE.Dept_date) Not Between [Forms]![SITE_RESERVATIONS]![Arr_date] And [Forms]![SITE_RESERVATIONS]![Dept_date] And (RESERVE.Dept_date)>Now())) OR (((RESERVE.[Site#]) Is Null));