Return unique years from find

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Rails: select unique values from a column

Lets say I have 5000 records that were created in the last two years (2011 & 2012). How can I loop through all those records and return an array of only the unique years [2011, 2012]?

I'm creating a report where rows are labeled by each year that records exit and columns are labeled by months. Then td is populated by sum totals for each month of each year.

score 5 · Accepted Answer · edited May 23 '17 at 10:30

5

see Rails: select unique values from a column for a more rails approach..

Model.uniq.pluck(:year)

edited:

for your specific requirment you can do

 Model.pluck(:created_at).map{|x| x.year}.uniq

edited May 23 '17 at 10:30

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answered Oct 12 '12 at 22:38

Nick Ginanto

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Nice! I didn't know about pluck(). – Brad Werth Oct 12 '12 at 22:43
This seems to be looking for a column named 'year'. No? – hellion Oct 12 '12 at 22:44
Model.uniq.pluck(:created_at) is getting close. But, it is returning uniq 'created_at' dates. I need unique years. Any ideas? – hellion Oct 12 '12 at 22:51
oh you dont have a year attribute? – Nick Ginanto Oct 13 '12 at 00:13
i've edited the answer to help you more – Nick Ginanto Oct 13 '12 at 07:15
I like your updated answer better than using EXTRACT as I did below. Thanks very much! – hellion Oct 13 '12 at 17:14

score 1 · Answer 2 · answered Oct 12 '12 at 23:00

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Model.select("created_at").map{ |i| i.created_at.year }.uniq is working. Im still digging around for a cleaner way to do it.

answered Oct 12 '12 at 23:00

hellion

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Went with this solution inspired by RailsN00b. Model.uniq.pluck("EXTRACT(YEAR FROM whatever_date)") – hellion Oct 12 '12 at 23:34

Return unique years from find

2 Answers2