#4882 ActiveRelation bug; size() returning incorrect value with limit(). - Ruby on Rails

Type	To find
responsible:me	tickets assigned to you
tagged:"@high"	tickets tagged @high
milestone:next	tickets in the upcoming milestone
state:invalid	tickets with the state invalid
created:"last week"	tickets created last week
sort:number, importance, updated	tickets sorted by #, importance or updated
Combine keywords for powerful searching.
Use advanced searching »

This project is archived and is in readonly mode.

#4882 ✓resolved

ActiveRelation bug; size() returning incorrect value with limit().

Reported by James Harton | June 17th, 2010 @ 01:34 AM

Easiest to explain with a snippet:

Loading development environment (Rails 3.0.0.beta4)
ruby-1.8.7-p249 > Post.limit(20).size
 => 1000 
ruby-1.8.7-p249 > Post.limit(20).all.size
 => 20

You flagged this item as spam.
PacoGuzman June 20th, 2010 @ 05:32 PM
When you're executing:

Post.limit(20).size

In the database the following sql query is executed:

SELECT COUNT(*) AS count_id FROM posts LIMIT 20;

And with that query the 'LIMIT' options isn't applied to the database. But in the other case we got:

Post.limit(20).all.size => SELECT * FROM posts LIMIT 20;

And the answer for the size of the array returned. So IMHO there isn't any problem with ActivceRelation
You flagged this item as spam.
James Harton June 20th, 2010 @ 09:43 PM
Ahh right! I understand. You don't think this is a little counter-intuitive?
José Valim June 22nd, 2010 @ 05:03 PM
- Assigned user set to “Emilio Tagua”
Emilio Tagua June 23rd, 2010 @ 06:10 PM
Hey,

I've fixed this in Arel. I attach patch with tests for AR.

Arel commits:

http://github.com/rails/arel/commit/71e92992e66f461acaabc3ac2f3ec64...

and

http://github.com/rails/arel/commit/a040b1c0e68f7a5145a6decf6731be9...
- tests.diff 2 KB
You flagged this item as spam.
James Harton June 24th, 2010 @ 01:32 AM
Wow, thanks!
Repository June 24th, 2010 @ 11:14 AM
- State changed from “new” to “resolved”
(from [5441e082f9478ddb3c676c681b09786f1391483c]) Add tests for relation count. Fix other tests that were conceptually wrong.

[#4882 state:resolved]

Signed-off-by: José Valim jose.valim@gmail.com
http://github.com/rails/rails/commit/5441e082f9478ddb3c676c681b0978...