Yes, that's the way to do it if the calculations must be done in Python. You can only use the direct update method if the database itself can do the calculations (via a SQL expression). For example, here is what you can do in PostgreSQL: http://www.postgresql.org/docs/9.4/static/functions-math.html.
Anthony On Wednesday, September 30, 2015 at 8:36:48 PM UTC-4, Dave S wrote: > > > > On Tuesday, September 29, 2015 at 1:25:33 PM UTC-7, Anthony wrote: >> >> You can do it in one line - just let the database do the incrementing by >> passing an expression in the .update() method: >> >> db(db.mytable).update(counter=db.mytable.counter + 1) >> >> Much more efficient because you don't have to load any records from the >> db or do any processing in Python. >> >> > > For the fearsome case where some additional python logic was needed to > compute the new value, would you use > newcount = complex_calc(row.count, obtuse_parameters) > row.update_record(count = newcount) > > or can lambda's be used in the db(...).update() call? > > /dps > > > > -- 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.
