Add support foreign key constraints

[strangerxx]

Sorting table in list

[jeremy-ebler-vineti]

This worked for me.

Changes to the gemspec should be left to the maintainer.

I liked the reflect_on_all_associations(:belongs_to) approach. I was considering querying against information_schema to find foreign key restraints, but I think the reflection approach will be more portable. 👍

The code itself isn't very pragmatic Ruby. For example, the Dump module shouldn't have a public class_exists? method, there is a lot of repetition that can be refactored to be more readable, and Array.new instead of simply [] stands out.

[lenlo]

This is all good, but a simpler solution might be to just turn off foreign key constraint checking while loading the data. This is the approach that both MySQL and SQLite3 takes for their own SQL dumps and can easily be achived by wrapping the body of load_documents in:

ActiveRecord::Base.connection.disable_referential_integrity do
  ...
end