Class: ARDBCopy

Inherits:
Object
  • Object
show all
Defined in:
lib/ar_dbcopy.rb

Defined Under Namespace

Classes: Application, SourceDB, TargetDB

Instance Method Summary collapse

Constructor Details

#initialize(config_file, opts = {}) ⇒ ARDBCopy

Returns a new instance of ARDBCopy.



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# File 'lib/ar_dbcopy.rb', line 25

def initialize(config_file, opts={})
  @copy_schema = opts[:copy_schema]

  config = YAML.load_file(config_file)

  ActiveRecord::Base.logger ||= Logger.new(nil)

  SourceDB.establish_connection(config["source"])
  ActiveRecord::Base.establish_connection(config["target"])

  @tables = SourceDB.connection.tables.reject { |m| m == "schema_migrations" }
end

Instance Method Details

#copy_data ⇒ Object 



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# File 'lib/ar_dbcopy.rb', line 52

def copy_data
  @tables.each do |table_name|
    source_model = Class.new(SourceDB) do
      set_inheritance_column(:not_sti)
      set_table_name table_name
    end

    dest_model = Class.new(TargetDB) do
      set_inheritance_column(:not_sti)
      set_table_name table_name
    end

    dest_model.delete_all

    puts "Copying #{table_name} (#{source_model.count} lines)..."

    i = 0
    source_model.find_in_batches(:batch_size => 10_000) do |src_batch|
      dest_model.transaction do
        src_batch.each do |src_inst|
          dst_inst = dest_model.new(src_inst.attributes)
          dst_inst.id = src_inst.id
          dst_inst.save!
          i += 1
        end

        puts i
      end
    end
  end
end

#copy_schema ⇒ Object 



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# File 'lib/ar_dbcopy.rb', line 43

def copy_schema
  io = StringIO.new

  ActiveRecord::SchemaDumper.dump(SourceDB.connection, io) # dump the schema from the source database
  io.rewind

  eval(io.read)
end

#run! ⇒ Object 



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# File 'lib/ar_dbcopy.rb', line 38

def run!
  copy_schema if @copy_schema
  copy_data
end