Rake task to convert MySQL DB's tables and columns to a specific encoding and collation.

convert_mysql_encoding.rb

namespace :db do
  desc "Convers the encoding and collation of database, tables and columns."
  task :convert_encoding, [:character_set, :collation] => :environment do |t, args|
    args.with_defaults(character_set: 'utf8', collation: 'utf8_general_ci')
    ActiveRecord::Base.connection.tables.each do |table|
      ActiveRecord::Base.connection.execute("ALTER TABLE `#{table}` CONVERT TO CHARACTER SET #{args.character_set} COLLATE #{args.collation};")
    end
  end
end

convert_mysql_encoding_console.rb

# or paste this into a rails console
character_set = 'utf8'
collation = 'utf8_general_ci'
ActiveRecord::Base.connection.tables.each do |table|
  ActiveRecord::Base.connection.execute("ALTER TABLE `#{table}` CONVERT TO CHARACTER SET #{character_set} COLLATE #{collation};")
end

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