the first is more efficient, cause it does a single query. web2py allows to
fetch "connected" records for each row, but is forced to fetch them one at
a time. Inspect with response.toolbar queries and timings and choose your
own poison (hefty query vs "speedier to code")
On Friday, June 7, 2013 6:41:05 PM UTC+2, Relsi Hur Maron wrote:
>
> Hi guys,
>
> I have a doubt here about he best way of show a *reference* value.
>
> I'll use a simple example to illustrate, I have the following tables:
>
>
> db.define_table('city',
> Field('name', type='string')
> )
> db.define_table('state',
> Field('name', type='string')
> )
> db.define_table('user',
> Field('user_name', 'string'),
> Field('user_city', 'reference city'),
> Field('user_state', 'reference state')
> )
>
>
> When I list the *user* table data in the view, *user_city* and *user_state
> * show their *id's*. It's OK.
>
> So, to display the value of another field, not the Id, I usually do so:
>
> In the controller:
>
>
> list = db(db.user.id>0).select(
> db.user.ALL,
> db.state.ALL,
> db.state.ALL,
> left = [
> db.state.on(db.state.id == db.user.user_state),
> db.city.on(db.city.id == db.user.user_city)
> ]
> )
> return dict(list=list)
>
>
> And in the view:
>
>
> {{for data in list:}}
> <tr>
> <td>{{=data.user.user_name}}</td>
> <td>{{=data.city.name}}</td>
> <td>{{=data.state.name}}</td>
> </tr>
> {{pass}}
>
> And it works very well, but I discovered here that I can make it in a more
> simple way:
>
> In controller:
>
> list = db(db.user.id >0).select()
> return dict(list=list)
>
> In the view:
>
> {{for data in list:}}
> <tr>
> <td>{{=data.user_name}}</td>
> <td>{{=("%(name)s" %data.user_city)}}</td>
> <td>{{=("%(name)s" %data.user_state)}}</td>
> </tr>
> {{pass}}
>
> So my question is if I can use this second format, without mounting a join
> as I did in the first example. What is the best (efficient) format? and why?
>
>
> Thanks to all!!
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
--
---
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 [email protected].
For more options, visit https://groups.google.com/groups/opt_out.
