Finding distinct values in array column

Question

I'm using Postgresql with ActiveRecord in Rails 4.

I have a customer model and one of the columns is called "tags" and it is an array column (["sports", "broadcasting"]).

How can I select all the distinct values from this column? I would like to avoid doing anything where I would have to instantiate AR objects due to the amount of customer records we have. So I don't want something like:

Customer.select(:tags).map(&:tags).flatten.uniq

which works but uses too much memory.

I need the values to provide suggestions when someone is adding a tag to a customer. Hopefully it will help prevent variations of words or misspellings.

Thanks in advance!

Try Customer.pluck(:tags).flatten.uniq

Pavan
– Pavan

2015-07-16 04:57:03 +00:00
Commented Jul 16, 2015 at 4:57 — Pavan
– Pavan, Commented Jul 16, 2015 at 4:57

Pavan · Accepted Answer · 2015-07-16 04:59:48Z

3

You can use pluck like below

Customer.pluck(:tags).flatten.uniq

answered Jul 16, 2015 at 4:59

Pavan

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