Re: [SQLObject] SUM

[Ian B. <ia...@co...>]

On Apr 5, 2004, at 3:24 PM, Philippe Normand wrote:
> On Sun, Apr 04, 2004 at 04:17:32PM -0500, Ian Bicking wrote:
>> On Apr 4, 2004, at 8:33 AM, Philippe Normand wrote:
>>> How can I use func.SUM() since it can't reside in where condition ?
>>> For COUNT(), there's a way with Table.select().count(). What's the
>>> trick for SUM() ?
>>> I didn't found any Table.select().sum('attribute')
>>
>> You can't really use SUM -- it's also left in sqlbuilder from
>> sqlbuilder's past life as a general query builder.  It would be
>> interesting to add that as a method to SelectResults, like count.
>>
>
> Would this patch answer your request ?

Looks okay.  I'd like to have tests to go with any new code, though.  
If tests/test.py is too hairy for you, a test in the form of an 
interactive script will do.

Also, it occurs to me that these are all about accumulation -- count, 
sum, max, min, and no doubt others.  It might be nice to generalize 
this, like SelectResult.accumulate(expression), where sum looks like:

def sum(self, column):
     return self.accumulate(sqlbuilder.func.SUM(column))

... though sum should probably also for a string column; accumulate 
doesn't have to check for that -- though if it is passed a string it 
should interpret it as a SQL expression, so you could do 
selectResult.accumulate('SUM(a_column)')

--
Ian Bicking | ia...@co... | http://blog.ianbicking.org