Question

I have this table in access and I’m trying to do a Count and a Group by but am getting an error.

What I’m trying to do is group by the source the number of cars which have AC and are made before 2008.

I tried this:

SELECT SOURCE_ID, COUNT (SOURCE_ID) AS VEHICLES_WITH_AC
FROM VEHICLE
WHERE VEH_AC = 'Y'
GROUP BY  SOURCE_ID, VEH_AC,  VEH_YEAR
HAVING VEH_YEAR <'2008';

But im getting:

Answer 1

SELECT SOURCE_ID, COUNT (*) AS VEHICLES_WITH_AC
FROM VEHICLE
WHERE VEH_AC = 'Y' AND VEH_YEAR < '2008'
GROUP BY  SOURCE_ID;

1) You apparently require totals by source_id and nothing else, so you don’t group by anything else.

2) your condition on VEH_YEAR should go in the where clause otherwise all veh_year rows will be selected and thrown away after aggregation.