Alban Hertroys wrote on 08.08.2010 10:46:
> On 7 Aug 2010, at 23:18, Thomas Kellerer wrote:
>
>> Or as an alternative:
>>
>> SELECT tid, purchase_date
>> FROM orders
>> WHERE item in ('Laptop', 'Desktop')
>> GROUP BY tid, purchase_date
>> HAVING count(*) = 2
>
>
> This one is incorrect, it will also find people who bought two laptops or two desktops on the same date.
Right. I didn't think about that ;)
> But I think David's solution is more readable, as it leaves the item names in tact.
I absolutely agree. Another example of PG's cool array handling :)
Regards
Thomas