SELECT query problem - session vars?

[sipps]

Hi all,

I am using PHP to write parts of my query to find a free car at a specific location with specific attributes such as Air_Con and Transmission and Fuel_Type. These values are passed from one page using session variables, along with the pick_up and drop_off dates and locations.

The dates and locations seem to work fine in teh quer, perhaps because they are integers or dates, but the air_Con, fuel_Type and transmission don't seem to affect the query at all and it brings back the same car reg whatever the input.

Here is the query:

SELECT DISTINCT vehicle.Vehicle_Registration
FROM vehicle LEFT JOIN booking
ON vehicle.Vehicle_registration = booking.Vehicle_Registration
WHERE Air_Con = '$HTTP_SESSION_VARS[Air_Con'
AND Fuel_Type = '$HTTP_SESSION_VARS[Fuel_Type]'
AND Transmission = '$HTTP_SESSION_VARS[Transmission]'
AND booking.Vehicle_Registration IS NULL
AND vehicle.Vehicle_Group_ID = '$_POST[Vehicle_Group_ID]'
AND Current_Location = '$HTTP_SESSION_VARS[Pick_Up_Location]' OR ('$HTTP_SESSION_VARS[Pick_Up_Date]' NOT BETWEEN Pick_Up_Date
AND Drop_Off_Date AND '$HTTP_SESSION_VARS[Drop_Off_Date]' NOT BETWEEN Pick_Up_Date AND Drop_Off_Date
AND Pick_Up_Date NOT BETWEEN '$HTTP_SESSION_VARS[Pick_Up_Date]' AND '$HTTP_SESSION_VARS[Drop_Off_Date]' AND Drop_Off_Date NOT BETWEEN '$HTTP_SESSION_VARS[Pick_Up_Date]' AND '$HTTP_SESSION_VARS[Drop_Off_Date]' AND '$HTTP_SESSION_VARS[Pick_Up_Date]' >= NOW())

Like I said, the date session_vars and location session_vars work fine and the right car comes back for that location and those dates, but the Air_Con doesn't affect it at all.

Even when I put the value 'Yes' or 'No', instead of '$HTTP_SESSION_VARS[Air_Con]' it doens't affect the query. Is this because of the LEFT JOIN?

I am quite new to MySQL so would really appreciate some help, this has been buggin me for days!!!

Thanks