Re: how to construct sql

On Wed, Jun 2, 2010 at 2:44 PM, Justin Graf <justin@magwerks.com> wrote:
> On 6/2/2010 12:31 PM, Wes James wrote:
>> On Wed, Jun 2, 2010 at 10:55 AM, Oliveiros
>> <oliveiros.cristina@marktest.pt>  wrote:
>>
>>> Hi,
>>> Have you already tried this out?
>>>
>>> select MAX(page_count_count) - MIN(page_count_count)  from page_count group
>>> by page_count_pdate.
>>>
>>>
>>> Best,
>>> Oliveiros
>>>
>> Oliveiros,
>>
>> Thx that mostly works.  I just tried it and on the days there is only
>> 1 entry it is 0 since max is the same as min so max - min is 0.  Is
>> there a way to take in to account the 1 entry days?
>>
>> Again thx - I appreciate your help :)
>>
>> -wes
>>
>>
> Put in a case
>
> select
> case when MAX(page_count_count) - MIN(page_count_count)>  0 then
>        MAX(page_count_count) - MIN(page_count_count)
> else
>        MAX(page_count_count)
> from page_count
> group by page_count_pdate.
>


Thx it is closer (with an end in the case):

select
case when MAX(page_count_count) - MIN(page_count_count) > 0 then      MAX(page_count_count) - MIN(page_count_count)
else      MAX(page_count_count)
end as day_max
from page_count
group by page_count_pdate order by page_count_pdate;

the else puts out the total count on that day.  I would need
max(page_count_count) - max(page_count_count_of_previous_day)

thx,

-wes