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#
# Convert/transfer data from production => development. This facilitates
# a conversion one database adapter type to another (say postgres -> mysql )
#
# WARNING 1: this script deletes all development data and replaces it with
# production data
#
# WARNING 2: This script assumes it is the only user updating either database.
# Database integrity could be corrupted if other users where
# writing to the databases.
#
# Usage: rake db:convert:prod2dev
#
# It assumes the development database has a schema identical to the production
# database, but will delete any data before importing the production data
#
# A couple of the outer loops evolved from
# http://snippets.dzone.com/posts/show/3393
#
# For further instructions see
# http://myutil.com/2008/8/31/rake-task-transfer-rails-database-mysql-to-postgres
#
# The master repository for this script is at github:
# http://github.com/face/rails_db_convert_using_adapters/tree/master
#
# Author: Rama McIntosh
# Matson Systems, Inc.
# http://www.matsonsystems.com
#
# This rake task is released under this BSD license:
#
# Copyright (c) 2008, Matson Systems, Inc. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# * Neither the name of Matson Systems, Inc. nor the names of its
# contributors may be used to endorse or promote products derived
# from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
namespace :db do
namespace :convert do
desc 'Convert/import production data to development. DANGER Deletes all data in the development database. Assumes both schemas are already migrated.'
task :prod2dev => :environment do
# We need unique classes so ActiveRecord can hash different connections
# We do not want to use the real Model classes because any business
# rules will likely get in the way of a database transfer
class ProductionModelClass < ActiveRecord::Base
end
class DevelopmentModelClass < ActiveRecord::Base
end
skip_tables = ["schema_info", "schema_migrations"]
ActiveRecord::Base.establish_connection(:production)
(ActiveRecord::Base.connection.tables - skip_tables).each do |table_name|
ProductionModelClass.set_table_name(table_name)
DevelopmentModelClass.set_table_name(table_name)
DevelopmentModelClass.establish_connection(:development)
DevelopmentModelClass.reset_column_information
ProductionModelClass.reset_column_information
DevelopmentModelClass.record_timestamps = false
# Page through the data in case the table is too large to fit in RAM
print "Converting #{table_name}... "; STDOUT.flush
# First, delete any old dev data
DevelopmentModelClass.delete_all
ProductionModelClass.find_each do |model|
# Now, write out the prod data to the dev db
DevelopmentModelClass.transaction do
new_model = DevelopmentModelClass.new(model.attributes)
new_model.id = model.id
new_model.save(:validate => false)
end
end
print ": #{DevelopmentModelClass.all.count} of #{ProductionModelClass.all.count} records\n"
end
end
end
end