OK, I know I can't get a sum of virtual fields, but here's what I'm trying to do:
db.define_table( 't_periods', Field('f_start', type='datetime', label=T('Start time')), Field('f_end', type='datetime', label=T('End time')), Field('f_task', type='reference t_tasks', label=T('Task')), ...) db.t_periods.f_duration = Field.Virtual('f_duration', lambda row: row.f_end - row.f_start) So, for any one task there may be multiple periods of time. I would like a list of tasks and the total time allocated to each. I tried this: task_duration = db.t_periods.f_duration.sum() results = db(query).select(db.t_tasks.f_name, task_duration, groupby=db.t_tasks.f_name) That gives me the error: AttributeError: 'FieldVirtual' object has no attribute 'sum' That makes sense to me, but what would be a good strategy to get a list of tasks and the total duration for each? Thanks -- Resources: - http://web2py.com - http://web2py.com/book (Documentation) - http://github.com/web2py/web2py (Source code) - https://code.google.com/p/web2py/issues/list (Report Issues) --- You received this message because you are subscribed to the Google Groups "web2py-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to web2py+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.