Get n record from each categorie in rails

Asked Nov 09 '15 at 17:09

Active Nov 10 '15 at 07:41

Viewed 49 times

I would like to get n random records from each category on my model but I don't know how to.

My table model

- id,category,name,date
- 7,A,foo,2015-01-01
- 8,B,bar,2014-01-14
- 9,B,foo,2014-01-15
- 10,C,toto,2015-11-09
- 11,C,tata,2015-11-09
- 12,A,aaaa,2015-11-09
- 13,B,bbbb,2015-11-09
- 14,C,test,2015-11-09
- 15,A,ccc,2015-11-09
- 16,B,dddd,2015-11-09
- 17,C,eeee,2015-11-09

The result I want for n = 2

15,A,ccc,2015-11-09
12,A,aaaa,2015-11-09
8,B,bar,2014-01-14
16,B,dddd,2015-11-09
17,C,eeee,2015-11-09
11,C,tata,2015-11-09

how can I do in rails ? I have no idea how to do it.

edited Nov 10 '15 at 07:41

asked Nov 09 '15 at 17:09

lokhi

SQL doesn't easily allow N from each, but instead 1 from each, or N maximum. Additionally, what results are you expecting here? – tadman Nov 09 '15 at 17:12
Check out this question, and everything else tagged [tag:greatest-n-per-group] for help http://stackoverflow.com/q/12113699/3131147 – AdamMc331 Nov 09 '15 at 17:28
@McAdam331 that example works only for groups ........ – Haider Ali Nov 09 '15 at 17:48
@HaiderAli I quote the question: "I would like to get n records from each group..." – AdamMc331 Nov 09 '15 at 17:49
Note that group is a reserved word – Strawberry Nov 09 '15 at 17:53
Thanks I have edited my post – lokhi Nov 10 '15 at 07:42

Get n record from each categorie in rails

0 Answers0