db.mytable(name=s) is shortcut for
db(db.mytable.name==s).select(limitby=(0,1)).first() On Monday, 21 November 2016 09:58:01 UTC-6, Ramos wrote: > > I used this compact way and i noticed it only returns one record. > > for example > > table db.badass > id name value > 1 trump 10 > 2 trump 20 > 3 hilary 30 > > db.badass(name="trump") > only returns record with id =1 > > Regards > António > > 2016-11-21 15:47 GMT+00:00 Massimo Di Pierro <[email protected]>: > >> It depends >> >> a query is always field==value so you can do >> >> query = db.table.field == value >> row = db(query).select(limitby=(0,10)).first() >> >> or >> >> row = db.table(query) >> >> (they are equivalent) >> >> But db.table(...) can take an "implicit query" >> >> db.table(fieldname=value) >> >> which is a more compact way to do >> >> db.table(db.table.field==value) >> >> The most common way to use db.table(...) is this >> >> db.table(id) >> >> or >> >> db.table(id, fieldname=value) # returns the record only of the >> fieldname==value >> >> or >> >> db.table(id, query) # returns the record only if the query is true. >> >> >> >> On Sunday, 20 November 2016 09:08:38 UTC-6, Meinolf wrote: >>> >>> Hi Massimo >>> >>> Just came across this post and got a bit alarmed, so when i check if a >>> record exists i don't have to use the usual '==' but instead '=' ? >>> >>> On Monday, October 10, 2011 at 3:55:27 PM UTC+2, Massimo Di Pierro wrote: >>>> >>>> row = db.postcode_cache(postcode=postcode) >>>> if not row: >>>> db.postcode_cache.insert(postcode=postcode,nearset=nearest) >>>> elif not row.nearest: row.update_record(nearset=nearest) >>>> else: pass # do nothing >>>> >>>> On Oct 10, 8:22 am, Chris Rowson <[email protected]> wrote: >>>> > Hi list, >>>> > >>>> > I have a database table which looks like this: >>>> > >>>> > postcode_cache >>>> > ------------------------ >>>> > postcode (UNIQUE) >>>> > lat >>>> > lon >>>> > nearest >>>> > >>>> > I want to test first whether or not a record exists for 'postcode' >>>> and >>>> > if a record does exist, I want to check whether the 'nearest' field >>>> > contains any data. >>>> > >>>> > I've tried this: >>>> > >>>> > if db(db.postcode_cache.postcode==postcode).select().first()==None: >>>> > create_a_new_postcode_record() >>>> > >>>> > elif >>>> db(db.postcode_cache.postcode==postcode).select(db.postcode_cache.nearest)= >>>> >>>> =None: >>>> > populate_the_nearest_field() >>>> > >>>> > else: >>>> > nothing_to_do() >>>> > >>>> > And while the check to establish whether or not a record exists seems >>>> > to work, the check to see whether or not the 'nearest' field within >>>> > the record is populated doesn't seem to work. >>>> > >>>> > Can anyone tell me what I'm doing wrong please? >>>> > >>>> > Thank you, >>>> > >>>> > Chris >>> >>> -- >> 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 [email protected]. >> 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 [email protected]. For more options, visit https://groups.google.com/d/optout.
