Доступ к дереву XML как к обычным объектам

Для этого можно использовать XSD::Mapping из стандартной библиотеки:

require ‘xsd/mapping’ 
people = XSD::Mapping.xml2obj(File.read("people.xml")) 
people.person[2].name # => "name3" 

Если в имени тэга присутствует дефис, можно сделать так: people[’foo-bar’]

Ну а выполнить обратное преобразование объектного дерева в XML поможет метод: XSD::Mapping.obj2xml

------------------------------------------------------------------- Time#strftime
time.strftime( string ) => string
---------------------------------------------------------------------------------
Formats time according to the directives in the given format string. Any text not listed as a directive will be passed through to the output string.

"
Format meaning:

%a - The abbreviated weekday name (``Sun'')
%A - The full weekday name (``Sunday'')
%b - The abbreviated month name (``Jan'')
%B - The full month name (``January'')
%c - The preferred local date and time representation
%d - Day of the month (01..31)
%H - Hour of the day, 24-hour clock (00..23)
%I - Hour of the day, 12-hour clock (01..12)
%j - Day of the year (001..366)
%m - Month of the year (01..12)
%M - Minute of the hour (00..59)
%p - Meridian indicator (``AM'' or ``PM'')
%S - Second of the minute (00..60)
%U - Week number of the current year,
starting with the first Sunday as the first
day of the first week (00..53)
%W - Week number of the current year,
starting with the first Monday as the first
day of the first week (00..53)
%w - Day of the week (Sunday is 0, 0..6)
%x - Preferred representation for the date alone, no time
%X - Preferred representation for the time alone, no date
%y - Year without a century (00..99)
%Y - Year with century
%Z - Time zone name
%% - Literal ``%'' character

t = Time.now
t.strftime("Printed on %m/%d/%Y") #=> "Printed on 04/09/2003"
t.strftime("at %I:%M%p") #=> "at 08:56AM"
"

There are alot of reasons to use stored procedures. One of the most compelling reasons is that a system has already been built with stored procedures and interfacing with it cannot be by raw SQL. This situation is mainly caused by DBA’s whose job it is to control the flow of information into and out of the database. In “enterprise” situations this is the norm.

  @connection = OCI8.new("db_user", "db_password", "db_name")

  plsql = @connection.parse("BEGIN P_MYPROCEDURE.my_method(:out); END;")
  plsql.bind_param(':out', OCI8::Cursor) 
  plsql.exec

  cursor = plsql[':out']
  plsql.close

  x = ''
  while r = cursor.fetch()
    x = x + r.join(', ') + '
'
  end

  @out = x

  @connection.logout

This code assumes you are using Rails 1.1 as an engine and that you have setup the database.yml for Oracle (10g in this post). The OCI8 object instantiated on the first line is in the OCI8 library which is loaded by Rails, specified in database.yml.

Interfacing with Oracle and its stored procedures pretty much requires some knowledge about Oracle which has some very specific concepts that something like MySQL does not.

First, to pass local variables to the stored procedure’s “in” and “out” variables, you must explicitly “bind” them.

Second is the notion of “cursor”.

Author: hksintl on http://blog.hksintl.com/