Re: need help to build a query

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On Tue, 10 Oct 2006 14:22:54 -0500, Richard Lynch wrote:
> On Mon, October 9, 2006 2:58 pm, John Wells wrote:
>> On 10/9/06, afan@xxxxxxxx <afan@xxxxxxxx> wrote:
>>> but I know there must be much better solution then this one.
>>
>> You're right: Simply JOIN your queries...
>>
>> SELECT order_id, order_date, order_status, file_name
>>     FROM orders
>>     JOIN uploaded_files AS uf ON orders.order_id = uf.order_id
>>     ORDER BY orders.order_id DESC
>>     LIMIT 100
> 
> This will "miss" all the orders with no upload at all, unlike the
> original.

As specified elsewhere in this thread, use outer join to prevent losing
orders with no uploads.

> AND it limits you to the 100 uploaded files, not 100 orders.
> 
> This is a lot more subtle problem than it seems at first glance, eh?

To fetch all uploaded filenames in one result row, and solving the limit
problem all at once, see group_concat(). Mind you, works only with MySQL
4.1...

Ivo

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