rows = db(query).select()
In the above, "rows" is a Rows object, which acts like a list of Row
objects. To extract a single Row object, you would do:
row = rows[index]
Specifically, to get the first Row, you would do:
first_row = rows[0]
rows.first() is simply equivalent to rows[0], except that if Rows happens
to be empty, instead of raising an exception, it will simply return None.
So, instead of doing:
first_row = rows[0] if rows else None
you can just do:
first_row = rows.first()
Anthony
On Friday, February 6, 2015 at 2:18:13 PM UTC-5, Alex Glaros wrote:
>
> can someone please consolidate my knowledge or tell me where in
> documentation this is explained
>
> the "first()" in this line below:
>
> this_message = db(db.InternalMessage.id ==
> request.get_vars.filter).select()*.first()*
>
> allows below to work in view:
>
> {{=this_message.created_by.last_name}}
>
> if the ".first()" is removed leaving this:
>
> this_message = db(db.InternalMessage.id == request.get_vars.filter).
> *select()*
>
> then view no longer works. First result is a single row, second result can
> be many rows.
>
> What is this concept called?
>
> Is first result a dictionary and second result a row?
>
> I understand that there is unacceptable ambiguity in the 2nd result with
> many possible rows but would like to know what the terms are called and
> where documented so I can read about it.
>
> Is .first() the only/best way to get a value into a single var (when no
> looping is necessary)?
>
> thanks
>
> Alex Glaros
>
--
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