Wrong number of arguments with SQL ISNULL() on Access DB

Question posted 2012 · +5 upvotes

I have this query in VB application on Access DB:

  SELECT DISTINCT Specialization, MAX(a.faultZone) AS faultZone, ISNULL(a.faultCount, 0) AS NoOfFaults  FROM Technicians AS t 
    LEFT JOIN 
             ( 
            SELECT DISTINCT Faults.[Type] AS faultType, MAX(Faults.[Zone]) AS faultZone, COUNT(Faults.[Type]) AS faultCount 
            FROM Faults "
            WHERE Faults.[Zone] = 8 " ' this value will be from variable
            GROUP BY Faults.[Type] "
            ) AS a 
    ON (t.Specialization = a.faultType) 
    WHERE t.specialization <> 'None' "
    GROUP BY a.faultCount, t.Specialization 

It gives following problem that I can’t solve…

“Wrong number of arguments used with function in query expression ‘ISNULL(a.faultCount, 0’.”

What I want to achieve is simply set value of NoOFFaults to zero, which would mean there are no faults in particular Zone.

Thank You