Rails Query limit

Question

I have a query of pictures like this

pictures = Picture.near([latitude, longitude], 6.8).where("created_at >= :time",{:time => time })

and I took out the tags which is associated with this model (every picture has_many :tags) like so

@tags = Tag.find(:all, :conditions => ["picture_id in (?)",pictures.collect(&:id)])

I used a query to pull out an attribute of each tag

@tags.map(&:tagcontent)

What I need to do is limit the results of the tags that come out. so I replaced

@tags = Tag.find(:all, :conditions => ["picture_id in (?)",pictures.collect(&:id)])

with this

numoftags = 6
tags = Tag.limit(numoftags).find(:all, :conditions => ["picture_id in (?)",pictures.collect(&:id)])

but this only yields 4 tags, when I know there is least 6 that can be pulled out. How should I modify this function.

Please post from your logs the SQL query that your code is generating. — jdl
– jdl, Commented Nov 14, 2011 at 19:24
RAILS_ROOT/log/development.log (or whatever environment you're running this under) — jdl
– jdl, Commented Nov 14, 2011 at 19:36

crazycrv · Accepted Answer · 2011-11-15 10:26:03Z

2

In Rails 3.X you can do something like this (using Arel)

numoftags = 6
@tags = Tag.where(["picture_id in (?)",pictures.collect(&:id)]).limit(nooftags)

answered Nov 15, 2011 at 10:26

crazycrv

2,4752 gold badges20 silver badges20 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

jack Over a year ago

this raised errors elsewhere in my app (which i fixed, but had to leave out your solution), but that was completely my fault for not explaining well enough, but this solved exactly what i asked for

Collectives™ on Stack Overflow

Rails Query limit

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related