Rake Task for truncating all tables in a rails app. Preserves the schema_migrations.

truncate_db_task.rb

  desc "Truncate all tables in the database"
  task :truncate_all_tables! => :environment do
    unless Rails.env.production?
      puts "TRUNCATING ALL TABLES in 3 seconds!!!!"
      sleep 3
      ActiveRecord::Base.connection.tables.each do |table|
        unless table == "schema_migrations"
          puts "Truncating #{table}."
          ActiveRecord::Base.connection.execute("TRUNCATE TABLE #{table} RESTART IDENTITY CASCADE;")
        else
          puts "skipping schema_migrations table"
        end
      end
    else
      puts "This task is not available in production!!!! It will destroy all data in the database."
    end
  end

If using Database Cleaner. Also this approach does not yield Environment data not found in the schema. To resolve this issue, run: error when running db:seed:replant after.

# lib/tasks/truncate_and_reset.rake
desc "Truncate all tables in the database and reset their primary indexes"
task :truncate_and_reset => :environment do
  return "Cannot run in production as all tables will be truncated!" if Rails.env.production?
  
  require 'database_cleaner/active_record'

  DatabaseCleaner.strategy = :truncation

  DatabaseCleaner.clean
  
  puts 'All tables truncated and primary indexes reset'
end