On 16/06/2009 19:12, Rob Sargent wrote the following:
> Richard Broersma wrote:
>> On Tue, Jun 16, 2009 at 2:40 PM, Rob Sargent<robjsargent@gmail.com>
>> wrote:
>>
>>
>>> Is there a city without a reference to region?
>>>
>>
>> I don't know, but the OP wanted to know complaints by region.
>>
>>
> I didn't try this, but with regionless cities, you may need a full join
> if you want a complete accounting of all complaints, some being logged
> to the null region.
>
>
>>
>>
>>
>>> And wouldn't you want to count(cm.id)?
>>>
>>
>> Count(cm.id) and Count(*) produce the same result. But I like
>> Count(*) more since it helps to correctly express the idea that we are
>> counting rows per group and not cm.id(s) per group.
>>
>>
>>
>>
>
> "Same result" is not true. I loaded tables.
> Using count(*) you get count=1 for regions without complaints. Using
> count(complaint.id) you get count = 0. (The deference amount to
> counting the left hand side (region) vs the right hand side (complaint)
> which I believe is what OP is after).
>
Thanks everyone for your help. Your solutions worked. Much appreciated.
- Carol
