selecting multiple primary key values

[vgurgov]

Hi there,

I have a table "software" which has area_id and soft_id (both make the primary key).

I need to make a query so that it would select all areas that have all of my selected software, ie:
select area_id
from software
where soft_id=13
and soft_id=22
and soft_id=49
(the number of soft_id's could vary 1-10)

This is, however, impossible because there are no rows that have soft_id equal to all those values because they are all unique rows.

So what I'm asking is if there is a keyword could be used that would do a multiple search like that. I tried the IN keyword:
select area_id
from software
where soft_id IN (13,22,49)
but this works like OR operation, and I need AND.

Thanks,
vg

[tomhath]

I haven't tested it, but you should be able to do something like this:

select area_id, count(*) as num_rows
from software
where soft_id IN (13,22,49)
group by area_id

Then in php, only display the area_id when num_rows equals the number of soft_id values you searched for (in this example, if the count is 3, you know the area_id has a row for all three of the soft_ids). This trick only works because the combination of aree_id and soft_id is the primary key.