I tried that. I get the error - <type 'exceptions.AttributeError'> 'Row' object has no attribute 'select' By the way, the "=" works. Additional information, this function is under modules. Do I have to imprt something to make the select construct work?
On Wed, Jan 22, 2014 at 5:22 PM, Johann Spies <johann.sp...@gmail.com>wrote: > Oops. That should be > cond = db(db.mytable.id==someid).select(db.mytable.id) > > > On 22 January 2014 13:50, Johann Spies <johann.sp...@gmail.com> wrote: > >> cond = db.mytable(id=someid).select(db.mytable.id) >> >> Regards >> Johann >> >> >> On 22 January 2014 10:50, Jayadevan M <maymala.jayade...@gmail.com>wrote: >> >>> I am checking for existence of record in a table >>> >>> cond = db.mytable(id=someid) >>> if not cond : >>> do something >>> >>> This works fine. The query executed selects *all* columns and adds >>> LIMIT 1 OFFSET 0; The LIMIT and OFFSET are OK. Since I want to just check >>> for existence of a record, how can I rewrite this so that we have only the >>> id column selected? I am trying to avoid a table scan and have just an >>> index scan. >>> >>> -- >>> 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 web2py+unsubscr...@googlegroups.com. >>> For more options, visit https://groups.google.com/groups/opt_out. >>> >> >> >> >> -- >> Because experiencing your loyal love is better than life itself, >> my lips will praise you. (Psalm 63:3) >> > > > > -- > Because experiencing your loyal love is better than life itself, > my lips will praise you. (Psalm 63:3) > > -- > 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 a topic in the > Google Groups "web2py-users" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/web2py/XYeLmZjQ6fY/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > web2py+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/groups/opt_out. > -- 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 web2py+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
