Retrieving only certain columns with Rails 3 where clause

Question

Not sure why I can't find out how to do this easily... Obviously I could do it with raw SQL, but I'm trying to familiarize myself with ActiveRecord.

results = Model.where(:lat => (south..north), :lng => (east..west))

I don't want all the fields, just a few. How would I limit the results to only include columns I choose?

Ray Baxter · Accepted Answer · 2011-07-11T20:38:30.590

32

results = Model.where(:lat => (south..north), :lng => (east..west)).select([:lat, :long, :id])

You'll also probably want to include the :id in that select if you want your results to behave like reasonable ActiveRecord objects.

Edit: Select takes a single arg, can be an array.

edited Jul 11 '11 at 20:38

answered Jul 11 '11 at 18:28

Ray Baxter

Thanks. One correction to your code above is what unixcharles said in his answer: argument for select needs to be an array of the fields or sql string. – Patm Jul 11 '11 at 18:38

score 4 · Answer 2 · answered Jul 11 '11 at 18:28

4

You need to use select

Model.where(...).select(...)

select accept array or raw sql string.

answered Jul 11 '11 at 18:28

Charles Barbier

score 0 · Answer 3 · answered Sep 25 '12 at 00:01

0

Technically, if you want to reuse the data subset filter for readonly models, you can create a 'view' at the database level. See http://dev.mysql.com/doc/refman/5.0/en/views.html

answered Sep 25 '12 at 00:01

Ivar

3 Answers3