Trying to figure out what valuable data I can get out of Mint's transactions.csv record

mint.rb

require 'csv'
require 'yaml'
require 'rails/all'
require 'active_record'
require 'active_support'
require 'sqlite3'

class Transaction < ActiveRecord::Base
  has_one :transaction_type
  has_one :category
  has_one :account
end

class TransactionType < ActiveRecord::Base
end
class Category < ActiveRecord::Base
end
class Account < ActiveRecord::Base
end

ActiveRecord::Base.establish_connection(
  adapter: 'sqlite3',
  database: 'mint.db'
)

def dateobj string
  m, d, y = string.split('/')
  d = [y,m,d].join('-').to_date
end

def create_database_from_csv
  if File.exist? 'mint.db'
    FileUtils.rm 'mint.db'
  end


  ActiveRecord::Migration.class_eval do
    create_table :transaction_types do |t|
      t.string :name
    end
    create_table :categories do |t|
      t.string :name
    end
    create_table :accounts do |t|
      t.string :name
    end
    create_table :transactions do |t|
      t.date :date
      t.string :description
      t.string :original_description
      t.integer :amount
      t.integer :transaction_type_id
      t.integer :category_id
      t.integer :account_id
      t.string :labels
      t.string :notes
    end
  end



  # "Date","Description","Original Description","Amount","Transaction Type","Category","Account Name","Labels","Notes"
  CSV.open('transactions.csv', headers: true) do |csv|
    csv.each do |t|
      x = t.to_hash
      x['Date'] = dateobj(x['Date'])
      x['Amount'] = x['Amount'].to_i
      Transaction.create! date: x['Date'],
        description: x['Description'],
        original_description: x['Original Description'],
        amount: x['Amount'],
        transaction_type_id: TransactionType.find_or_create_by_name(x['Transaction Type']).id,
        category_id: Category.find_or_create_by_name(x['Category']).id,
        account_id: Account.find_or_create_by_name(x['Account Name']).id,
        labels: x['Labels'],
        notes: x['Notes']
    end
  end
end

puts "For each month, credit - debit:"

first_transaction = Transaction.order('date ASC').first
last_transaction = Transaction.order('date DESC').first
done_months = []
(first_transaction.date..last_transaction.date).each do |date|
  m = date.month
  if m < 10
    m = "0#{m}"
  end
  y = date.year
  flag = [y,m].join('-')
  next if done_months.include? flag

  b = date.beginning_of_month.to_s(:db)
  e = date.end_of_month.to_s(:db)
  t_this_month = Transaction.where "date > ? and date < ?", b, e
  credits = t_this_month.where 'transaction_type_id = 2 and account_id in (2, 10)'
  debits =  t_this_month.where 'transaction_type_id = 1 and account_id in (1, 15)'
  credits_sum = credits.map(&:amount).inject(&:+) || 0
  debits_sum = debits.map(&:amount).inject(&:+) || 0

  puts "#{flag} =>".rjust(10, ' ')
  puts "\t#{credits_sum}".rjust(6, ' ')
  puts "\t#{debits_sum}".rjust(6, ' ')
  puts "\t" + (credits_sum - debits_sum).to_s

  done_months << flag
end