Class: SerializationHelper::Load

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

Direct Known Subclasses

CsvDb::Load, JsonDb::Load, YamlDb::Load

Class Method Summary collapse

Class Method Details

.database_type ⇒ Object 



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# File 'lib/serialization_helper.rb', line 145

def self.database_type
  case ActiveRecord::Base.connection.class.name
  when 'ActiveRecord::ConnectionAdapters::PostgreSQLAdapter'
    :postgresql
  when 'ActiveRecord::ConnectionAdapters::Mysql2Adapter', 'ActiveRecord::ConnectionAdapters::MysqlAdapter'
    :mysql
  end
end

.defer_fk_constraints(&block) ⇒ Object 



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# File 'lib/serialization_helper.rb', line 124

def self.defer_fk_constraints(&block)
  case database_type
  when :postgresql
    # make all fk constraints deferrable
    tables.each do |table|
      fk_constraints_on_table = ActiveRecord::Base.connection.foreign_keys(table)
      fk_constraints_on_table.each do |fk_constraint|
        quoted_table_name = SerializationHelper::Utils.quote_table(table)
        ActiveRecord::Base.connection.execute("ALTER TABLE #{quoted_table_name} ALTER CONSTRAINT #{fk_constraint.name} DEFERRABLE INITIALLY IMMEDIATE")
      end
    end
    # defer all fk constraints
    ActiveRecord::Base.connection.execute("SET CONSTRAINTS ALL DEFERRED")
    yield block
  when :mysql
    ActiveRecord::Base.connection.execute("SET foreign_key_checks = 0")
    yield block
    ActiveRecord::Base.connection.execute("SET foreign_key_checks = 1")
  end
end

.load(io, truncate = true) ⇒ Object 



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# File 'lib/serialization_helper.rb', line 67

def self.load(io, truncate = true)
  ActiveRecord::Base.connection.transaction do
    defer_fk_constraints do
      truncate_all if truncate
      load_documents(io)
    end
  end
end

.load_records(table, column_names, records, records_per_page = 1000) ⇒ Object 



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# File 'lib/serialization_helper.rb', line 102

def self.load_records(table, column_names, records, records_per_page=1000)
  if column_names.nil?
    return
  end
  columns = column_names.map{|cn| ActiveRecord::Base.connection.columns(table).detect{|c| c.name == cn}}
  quoted_column_names = column_names.map { |column| ActiveRecord::Base.connection.quote_column_name(column) }.join(',')
  quoted_table_name = SerializationHelper::Utils.quote_table(table)

  0.step(records.count-1, records_per_page) do |offset|
    all_quoted_values = records[offset, records_per_page].map do |record|
      '(' + record.zip(columns).map{|c| ActiveRecord::Base.connection.quote(c.first, c.last)}.join(',') + ')'
    end.join(', ')
    ActiveRecord::Base.connection.execute("INSERT INTO #{quoted_table_name} (#{quoted_column_names}) VALUES #{all_quoted_values}")
  end
end

.load_table(table, data) ⇒ Object 



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# File 'lib/serialization_helper.rb', line 95

def self.load_table(table, data)
  return if table == 'ar_internal_metadata'
  column_names = data['columns']
  load_records(table, column_names, data['records'])
  reset_pk_sequence!(table)
end

.reset_pk_sequence!(table_name) ⇒ Object 



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# File 'lib/serialization_helper.rb', line 118

def self.reset_pk_sequence!(table_name)
  if ActiveRecord::Base.connection.respond_to?(:reset_pk_sequence!)
    ActiveRecord::Base.connection.reset_pk_sequence!(table_name)
  end
end

.tables ⇒ Object 



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# File 'lib/serialization_helper.rb', line 90

def self.tables
  ActiveRecord::Base.connection.tables
end

.truncate_all ⇒ Object 



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# File 'lib/serialization_helper.rb', line 76

def self.truncate_all
  quoted_tables = tables.map do |table|
    SerializationHelper::Utils.quote_table(table)
  end
  case database_type
  when :postgresql
    ActiveRecord::Base.connection.execute("TRUNCATE #{quoted_tables.join(',')} CASCADE")
  when :mysql
    quoted_tables.each do |quoted_table|
      ActiveRecord::Base.connection.execute("TRUNCATE #{quoted_table}")
    end
  end
end