activerecord-mysql2spatial-adapterはRails + MySQLで位置情報を扱う場合に使用される事があるGemです。 https://github.com/rgeo/activerecord-mysql2spatial-adapter は、ややメンテナンスされていない印象を受けます。 Rails 5.1.6にて、使用するとこんな感じ。 $ bin/rake db:migrate rake aborted! NoMethodError: undefined method `attribute_types_cached_by_default' for ActiveRecord::Base:Class Did you mean? attribute_type_decorations
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