Also no-transactions (except for explicit record level transactions),
no OR in joins, not joins, not select(distinct=True), no
select(having=...). These are all GAE limitations.
On Jun 5, 4:47 am, Phyo Arkar <phyo.arkarl...@gmail.com> wrote:
> Finally Here is what i found after an hr of digging web2py group:
>
> fmax=db.table.field.max(),
> fmin=db.table.field.min()
> fcount=db.table.field.count()
> fsum=db.table.field.sum())
> rows = db(query).select(fmax,fmin,fcount,fsum)
> vmax=rows[0][fmax]
> vmin=rows[0][fmin]
> vavg=rows[0][fsum]/(rows[0][fcount] or 1)
>
> does not work on GAE
>
> On 6/5/11, Phyo Arkar <phyo.arkarl...@gmail.com> wrote:
>
>
>
>
>
>
>
> > I am also needing to find out max value of a field , seems like it is
> > undocumented.
>
> > Is it exist? Where in api doc should i look for.
>
> > On 4/4/11, Anthony <abasta...@gmail.com> wrote:
> >> On Monday, April 4, 2011 9:39:31 AM UTC-4, Neveen Adel wrote:
>
> >>> Thanks a lot Massimo :)
>
> >>> The problem with this solution is that i have a table has member_id as
> >>> foreign key and by this solution that data will be lost.
>
> >> Are you saying in the legacy database, the 'member' table has a
> >> 'membership_id' field, which is an auto-increment integer field and is
> >> linked as a foreign key in one or more other tables? In that case, why
> >> wouldn't Massimo's suggestion work? If you specify Field('membership_id',
> >> type='id'), you are telling web2py not to create a field named 'id', but
> >> instead to use the 'membership_id' field as the auto-incrementing primary
> >> key for the 'member' table. I would think it would still work as a
> >> foreign
> >> key in other tables in that case. Have you tried it?
>
> >> Also, as an aside, if you need the MAX of a field, I believe the web2py
> >> DAL
> >> has a max() method (as well as min and sum), but it doesn't appear to be
> >> documented in the book, and I'm not sure about the details of its usage.
> >> Perhaps Massimo or someone else can elaborate (and maybe even update the
> >> book).
>
> >> Anthony
>
> >>> On Apr 4, 3:31 pm, Massimo Di Pierro <massimo....@gmail.com>
> >>> wrote:
> >>> > how about
>
> >>> > db.define_table("member",
> >>> > SQLField("membership_id", "id"),
> >>> > SQLField("first_name", "string", notnull=True)
> >>> > )
>
> >>> > and "membership_id" would be your "id" field?
>
> >>> > On Apr 4, 8:03 am, Neveen Adel <nevo...@gmail.com> wrote:
>
> >>> > > Thanks Anthony for your reply.
>
> >>> > > The table already have an old data so i can't remove the column id
> >>> > > or
> >>> > > change in the database structure.
>
> >>> > > Is there another solution in controller level not database level?
>
> >>> > > Thanks in Advance
>
> >>> > > On Apr 4, 2:54 pm, Anthony <abas...@gmail.com> wrote:
>
> >>> > > > Your table already includes an 'id' field by default, which is an
> >>> > > > auto-increment integer field starting at 1. Why do you need a
> >>> separate
> >>> > > > 'membership_id' field? If it's a legacy database and you need the
> >>> name of
> >>> > > > the 'id' field to be 'membership_id', you can simply define the
> >>> > > > field
> >>> type
> >>> > > > as 'id' (seehttp://
> >>> web2py.com/book/default/chapter/06?search=auto-increment
> >>> > > > ).
>
> >>> > > > Also, you should use Field() instead of SQLField() -- they're both
> >>> the same,
> >>> > > > but the latter has been deprecated in favor of the former.
>
> >>> > > > Anthony
>
> >>> > > > On Monday, April 4, 2011 8:35:00 AM UTC-4, Neveen Adel wrote:
> >>> > > > > Hello,
>
> >>> > > > > I have the following table:
>
> >>> > > > > db.define_table("member",
> >>> > > > > SQLField("membership_id", "integer",notnull=True),
> >>> > > > > SQLField("first_name", "string", notnull=True)
> >>> > > > > )
>
> >>> > > > > and i want the membership id to be incremented automatically.
>
> >>> > > > > the way i used :
>
> >>> > > > > every time i inserted it , i select the max membership_id and
> >>> adding
> >>> > > > > one on its value as:
>
> >>> > > > > result=db.executesql("select max(membership_id) from member")
> >>> > > > > record=result[0]
> >>> > > > > if record[0]:
> >>> > > > > next_membership_id = record[0]+1
> >>> > > > > else:
> >>> > > > > next_membership_id=1
> >>> > > > > form.vars.membership_id=next_membership_id
>
> >>> > > > > But this solution allows duplicates??
>
> >>> > > > > could anyone tell me what is the perfect solution?
>
> >>> > > > > Thanks in Advance
