Update Postgres id sequences on all of your Rails models

update_postgres_id_sequences_in_rails_models.rb

Dir[Rails.root.join('app', 'models', '*')].each do |path|
  file = File.basename(path, '.rb')
  begin
    klass = file.classify.constantize
  
    if klass.respond_to?(:select)
      max_id = klass.maximum(:id).to_i + 1
      sequence = ActiveRecord::Base.connection.execute("SELECT nextval('#{klass.table_name}_id_seq')").first['nextval'].to_i
      if sequence <= max_id
        puts "Updating sequence for #{klass.table_name}"
        ActiveRecord::Base.connection.execute("SELECT setval('#{klass.table_name}_id_seq', (SELECT MAX(id) FROM #{klass.table_name}))")
      end
    end
  rescue ActiveRecord::StatementInvalid
    puts "Something was wrong with SQL in #{File.basename(file)}"
  rescue NameError
    puts "#{File.basename(file)} does not exist"
  end
end