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Igor Kasyanchuk
Igor Kasyanchuk

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Group with ranges for ActiveRecord

If you need to query your Active Record model and group by ranges or multiple values for a specific field - you can try my own gem:

https://github.com/igorkasyanchuk/calculate_in_group

Let's say you have task to count how many Users you have who have 1-5, 5-10, 10+ projects. Solution is simple:

User.calculate_in_group :count, :projects_count, [ 0, 1..5, 5..10, 10..100, 100.. ]
# => {"0"=>555, "1..5"=>145, "10..100"=>3991, "100.."=>190, "5..10"=>2824} 
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More Examples:

# Grouping can be used with :count, :average, :sum, :maximum, :minimum.

# Group with Ranges
User.calculate_in_group(:count, :age, [...10, 10...50, 50..] # => {"...10"=>1, "10...50"=>3, "50.."=>3}
User.calculate_in_group(:count, :created_at, { "old" => 12.hours.ago..1.minutes.ago, "new" => Time.now..10.hours.from_now }) # => {"old" => 2, "new" => 1}
User.calculate_in_group :count, :projects_count, [ 0, 1..5, 5..10, 10..100, 100.. ] # => {"0"=>555, "1..5"=>145, "10..100"=>3991, "100.."=>190, "5..10"=>2824} 

# Group with arrays or just values
User.calculate_in_group(:count, :role, "with_permissions" => ["admin", "moderator"], "no_permissions" => "user") # => {"with_permissions" => 3, "no_permissions" => 3}

# Other agg functions
User.calculate_in_group(:average, :age, "young" => 0..25, "old" => 60..100) # => {"young" => 11.0, "old" => 80.0}
User.calculate_in_group(:average, :age, "young" => 0..25, "old" => 60...100) # => {"young" => 11.0, "old" => 60.0}
User.calculate_in_group(:maximum, :age, "young" => 0..25, "old" => 60..100) # => {"young" => 20, "old" => 100}
User.calculate_in_group(:minimum, :age, "young" => 0..25, "old" => 60..100) # => {"young" => 3, "old" => 60}
User.calculate_in_group(:sum, :age, "young" => 0..25, "old" => 60..100) # => {"young" => 33, "old" => 160}
User.calculate_in_group(:sum, :age, {"young" => 0..25, "old" => 60..100}) # => {"young" => 33, "old" => 160}

# You can specify "other values" (with custom label) which are out of ranges
User.calculate_in_group(:count, :age, {"young" => 10, "average" => 25, "old" => 60}, {include_nil: "OTHER"}) # => {"young" => 1, "old" => 1, "OTHER" => 7}

# You can specify default value for keys which are missing in query
User.calculate_in_group(:count, :age, {"young" => 10, "average" => 25, "old" => 60}, { default_for_missing: 0 }) # => {"young" => 1, "old" => 1, "average" => 0}

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Look forward hearing your feedback :)

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