Re: query help

Jim C. Nasby wrote:
> On Wed, Jul 26, 2006 at 01:37:05PM +0200, Brendon Gleeson wrote:
>
>>I have a table called "marketing_campaigns":
>>
>>marketing_campaigns:
>>+----+--------------+------------+-------------+-------------
>>| id | date_started | date_ended | property_id | status
>>+----+--------------+------------+-------------+-------------
>>| 1 | 2005-01-01 | 2005-03-12 | 5 | sold
>>| 2 | 2006-01-11 | 2006-02-23 | 5 | jointly sold
>>| 3 | 2006-05-13 | NULL | 5 | for sale
>>| 4 | 2006-02-01 | 2006-02-06 | 6 | sold
>>
>>I am having trouble trying to say: Only show old campaigns And only if
>>their is not a "current" campaign for this property(property_id)
>
>
> #define 'old campaigns' and 'current'
>
>
>>The result of the query should only return row 4. Is their a way to do this
>>in sql without resorting to proprietary functions, or should I resort to
>>using Ruby (rails app)
>
>
> No, this can certainly be done in SQL, though if you have pseudo or ruby
> code on how you'd do it, it might make it a bit more clear on what
> you're after.

I can't test this at the moment but how about something like this.

SELECT *
FROM marketing_campaigns
WHERE date_ended IS NOT NULL
AND property_id NOT IN ( SELECT property_id
FROM marketing_campaigns
WHERE date_ended IS NULL
)
ORDER BY id;

--

Kind Regards,
Keith