def add_column(table_name, column_name, type, options = {})
execute("ALTER TABLE #{quote_table_name(table_name)} ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit])}")
change_column_default(table_name, column_name, options[:default]) unless options[:default].nil?
if options[:null] == false
execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)} = '#{options[:default]}'") if options[:default]
execute("ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} SET NOT NULL")
end
end