Rails how to sum columns?

ruby-on-rails ruby ruby-on-rails-3 ruby-on-rails-3.1
Rails beginner picture Rails beginner · Jan 16, 2012 · Viewed 42.3k times · Source

Example I have:

@test = Pakke.find([[4], [5]])

In my Pakke table I have a column named prismd

How do I sum the two values for the prismd columns for @test?

Answer

Holger Just picture Holger Just · Jan 16, 2012

You can summarize directly on the database by creating the respective SQL like this:

Pakke.sum(:prismd, :conditions => {:id => [4,5]})

See ActiveRecord::Calculations for more usage examples and general documentation.

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