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neaf/remove_columns.rb

Created May 31, 2013 10:38
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Deploy this initializer before migrations involving dropping/changing names of columns
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remove_columns.rb
model = MyModel
column_names = %w{ first_column second_column }
columns = model.columns.select { |c| column_names.include?(c.name) }
columns.each do |c|
model.columns.delete(c)
end
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neaf commented May 31, 2013

If you just run migration with drop column statement ActiveRecord in your app instance will continue to issue queries with non-existing items in column list causing exceptions.

To avoid downtime deploy this initialzier before dropping columns.

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