Re: [SQLObject] Subquery MAX().

[Oleg B. <ph...@ph...>]

On Fri, Dec 24, 2010 at 10:09:49AM -0500, Ben Timby wrote:
> Thanks for your reply Oleg. I am sorry, but the above produces a bad query:
> 
> --
> query = Sync.select(
>     AND(
>         Sync.q.syncpoint==self,
>         Sync.q.serial==sqlbuilder.Select(MAX('serial'),
> Sync.q.syncpoint==self, staticTables=('sync',))
>     )
> )
> --
> SELECT sync.id, sync.syncpoint_id, sync.serial, sync.stamp,
> sync.status, sync.message FROM sync WHERE (((sync.syncpoint_id) = (1))
> AND ((sync.serial) = (SELECT 'max(serial)' FROM sync WHERE
> ((sync.syncpoint_id) = (1)))));
> --
> 
> As you can see, the 'max(serial)' ends up inside quotes within the
> subselect. I can't find any MAX aggregate function to use in place of
> the string...

   Oops, columns in Select cannot be strings - to allow strings in
queries.

   Use sqlbuilder.Select(sqlbuilder.func.MAX(sqlbuilder.const.serial)

from sqlobject.sqlbuilder import Select, func, const
Select(func.MAX(const.serial)

   looks better for my eyes.

Oleg.
-- 
     Oleg Broytman            http://phdru.name/            ph...@ph...
           Programmers don't die, they just GOSUB without RETURN.