Here is a simple request:
Visit.group("user_id")
And I get:
PGError: ERROR: column "visits.id" must appear in the GROUP BY clause
or be used in an aggregate function
If I add visits.id to the group by clause, then it asks me to add
another column, then another, then another. Basically I have to list all
columns in the table!
What''s going wrong? From the Rails guide it seemed straightforward.
Thanks for your help
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Eureka! The docs are incomplete. I obviously need to add a count, sum, etc method for the grouping to make sense. -- Posted via http://www.ruby-forum.com/. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
I checked my install and received the same results. Looks like a PostgreSQL syntax thing. I''m new to PostgreSQL and have not looked at group by SQL syntax. Off the top of my head, as a (non recommended) work around, you could insert a .select() with a column list, and it should work. That, however, is a bad solution for obvious reasons, but might work in a pinch. I tried, and received the same result: User.group(:first_name) The following worked: User.select(:first_name).group(:first_name) -- Posted via http://www.ruby-forum.com/. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
Actually, as I think about it, you shouldn''t have a Select * in a Group By? You should select the column(s) you want to aggregate. Check this out: http://stackoverflow.com/questions/1769361/postgresql-group-by-different-from-mysql -- Posted via http://www.ruby-forum.com/. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
> I tried, and received the same result: > > User.group(:first_name)The thing is, we group for a reason. So PostgreSQL is expecting that reason to appear, e.g: count(), sum(), etc. -- Posted via http://www.ruby-forum.com/. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.