Great, i believe it clarifies a lot of misunderstanding from my side :-). Basically, correct me if am wrong: - the query is only evaluated at the time of the "select". - we can create "query" object for both parts of the query and assemble them and they 'll be evaluated at the time of the "select" - when we create such "query" object in the select part, the result for each row can be accessed using the query object (because the query object is automatically evaluated to a string that is the key to the storage of the value in the row dictionnary) - there was no chance for any of my attempt to work,because it was too late (first() condition on a query already evaluated...)
I start to love web2py :-) On 30 nov, 20:27, Carlos Hanson <[email protected]> wrote: > It is probably useful to see the following as well: > > >>> sum = db.operations.amount.sum().coalesce_zero() > >>> sum > > <gluon.dal.Expression object at 0x12e68d0>>>> print sum > > COALESCE(SUM(operations.amount),0) > > >>> monthly_amount_first = db((db.operations.date.year()==current_year) & > > ... (db.operations.date.month()==current_month) > ... ).select(sum).first()>>> monthly_amount_first > > <Row {'_extra': <Row {'COALESCE(SUM(operations.amount),0)': 45.0}>}>>>> > monthly_amount_first[sum] > > 45.0
