Actually you cannot this with the DAL. Since this is a one-time step,
I would do
db.executesql("UPDATE dest SET dest.field = (SELECT src.field FROM
src, dest WHERE src.dest_id = dest.id);")
On Nov 19, 11:21 am, Audra Rudys <sphin...@gmail.com> wrote:
> Oops, for logical clarity, it should be:
> UPDATE dest
> SET dest.field =
> (SELECT src.field FROM src, dest WHERE src.dest_id = dest.id);
>
> On Fri, Nov 19, 2010 at 11:20 AM, Audra Rudys <sphin...@gmail.com> wrote:
> > I figured out a way to do this... rewrote my query as a nested select:
> > UPDATE dest SET dest.field = (SELECT src.field FROM src, dest WHERE
> > src.dest_id = dest.id);
>
> > Does SQLite support UPDATE statements with multiple tables or does one have
> > to nest select statements to achieve this?
>
> > Thanks,
> > Audra
>
> > On Fri, Nov 19, 2010 at 10:56 AM, Audra Rudys <sphin...@gmail.com> wrote:
>
> >> This ought to be simple and yet...
> >> How do I write the following query in web2py?
> >> UPDATE dest, src
> >> SET dest.field = src.field
> >> WHERE src.dest_id = dest.id
>
> >> I only need to run it once. Tried via database administration module, but
> >> the problem seems to be that the source and destination field names are the
> >> same.
>
> >> Via code, if I write:
> >> db(db.dest.src_id == db.src.id).update(field = db.src.field)
> >> I get an error that SET doesn't know what to do.
>
> >> The syntax checker won't allow me to write (keyword can't be an
> >> expression):
> >> db(db.dest.src_id == db.src.id).update(dest.field = db.src.field) or
> >> db(db.dest.src_id == db.src.id).update(db.dest.field = db.src.field)
>
> >> I tried to execute the query using executesql and got an error as well:
>
> >> Traceback (most recent call last):
>
> >> File "E:\web2py\gluon\restricted.py", line 188, in restricted
>
> >> exec ccode in environment
>
> >> File "E:/web2py/applications/octopus/models/db_octopus.py"
> >> <http://127.0.0.1:8000/admin/default/edit/octopus/models/db_octopus.py>,
> >> line 44, in <module>
>
> >> db.executesql('UPDATE db.page_content,db.work SET
> >> db.page_content.created_by = db.work.created_by WHERE
> >> db.page_content.work_id == db.work.id;')
>
> >> File "E:\web2py\gluon\sql.py", line 1451, in executesql
>
> >> self._execute(query)
>
> >> File "E:\web2py\gluon\sql.py", line 963, in <lambda>
>
> >> self._execute = lambda *a, **b: self._cursor.execute(*a, **b)
>
> >> OperationalError: near ",": syntax error
>
> >> ...
>
> >> In case it's useful, variable a = ('UPDATE db.page_content,db.work SET
> >> page_content....d_by WHERE db.page_content.work_id == db.work.id;',)
>
> >> I've tried a few variations of the syntax, but still getting these errors.
> >> Please help!
>
> >> Audra
>
>
