Thank u leonel n Anthony. That was very helpful. Nice to have so many experts on this site! On Feb 24, 2015 9:58 AM, "Leonel Câmara" <leonelcam...@gmail.com> wrote:
> 1) > > db is your instance of the DAL class. A class in python can have a > __call__ method. If it does, instances of that class can be called like > functions. Which is what your doing here with db(...). > > In this case the DAL's *__call__ *takes a query or nothing and returns a *Set > *(not a python set, it's a DAL class). To make this query is why you have > the second db. There's another method in the DAL called *__getattr__ *which > allows you to get the tables from the DAL defined with *define_table *by > using dot notation. So what you're doing here is ask the DAL instance to > give you the table category. > > So now we know what this means: > my_set = db(db.category) > > *You're asking for a Set with the table category.* > > *select* is a method of *Set* which pretty much is equivalent to SQL's > select and returns *Rows*. Which is what you then do with: > > my_set.select(orderby=db.category.name) > > This can be simplified by simply calling select on the returning Set > immediately so you don't need a variable for the set if you just want the > Rows. > > categories = db(db.category).select(orderby=db.category.name) > > In this case, on the orderby, first you get the table from db using > getattr and then you get the *Field*, which you want to use to order, > from the table. > > > > That said, you don't need to know any of this, just learn the DAL's syntax > like Anthony said. > > -- > 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 a topic in the > Google Groups "web2py-users" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/web2py/jUQ8G3GCdBw/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > web2py+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- 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.
