From http://www.softiesonrails.com/articles/2006/06/28/activerecord-with-sqlserver-without-rails:

Ensure you done the initial setup for SQL Server and ActiveRecord (ADO.rb).

   1  
   2  require 'rubygems'
   3  require_gem 'activerecord'
   4  
   5  ActiveRecord::Base.establish_connection(
   6    :adapter  => "sqlserver",
   7    :dsn => "instance_name_goes_here",
   8    :host => "machine_name\\instance_name",
   9    :database =>  "db_name",
  10    :username =>  "my_username",
  11    :password =>  "my_password"
  12  )
  13  
  14  class MsSqlTable < ActiveRecord::Base
  15    def method_missing(method, *args)
  16      respond_to?(method) ? super : send(method.to_s.camelize, *args)
  17    end
  18  end
  19  
  20  class Item < MsSqlTable
  21    set_primary_key "sku"
  22    set_table_name "item"
  23  end

I'll walk through it real quick:

1. The :dsn needs to be your SQL Server instance name
2. The :host needs to a path like "myserver\myinstance", even though you've already specified the instance name in the :dsn parameter
3. The rest of the settings should be obvious. If your password is blank, don't specify :password at all.
4. Our legacy column names are things like OldDescription. So I created an intermediate base class that would provide ruby-like aliases. Now I can use item.old_description instead if I want to.
5. Finally, I declare one class for each table I want to access. I have to set the primary key and table name manually, since our tables don't correspond to any Rails conventions.

I saved this script as legacy.rb, and then fired up irb from that directory:

   1  
   2  irb> load 'legacy.rb'
   3  => true
   4  irb> Item.find("191191").old_description
   5  => "Table In A Bag"
   6  irb>

This force a recompile of all stored procs, views, tables, triggers, and functions in the current database.

   1  
   2  CHECKPOINT 
   3  GO
   4  
   5  DBCC DROPCLEANBUFFERS
   6  GO
   7  
   8  DBCC FREEPROCCACHE
   9  GO
  10  
  11  DECLARE @intDBID INTEGER 
  12  SET @intDBID = DB_ID()
  13  
  14  DBCC FLUSHPROCINDB (@intDBID)
  15  GO
  16  
  17  
  18  declare @procNames Table (procName varchar(255))
  19  insert into @procNames
  20  select name from sysObjects where xtype in ('V','P','U','FN','TF','TR' ) and status > 0
  21  
  22  --select * from @procNames
  23  
  24  set nocount off
  25  --3. Run each command
  26  -- =============================================
  27  -- Declare and using a READ_ONLY cursor
  28  -- =============================================
  29  DECLARE RecompilableItemsCursor CURSOR
  30  READ_ONLY
  31  FOR select procName from @procNames
  32  
  33  DECLARE @RecompilableItem varchar(255)
  34  OPEN RecompilableItemsCursor
  35  
  36  
  37  FETCH NEXT FROM RecompilableItemsCursor INTO @RecompilableItem
  38  WHILE (@@fetch_status <> -1)
  39  BEGIN
  40  	IF (@@fetch_status <> -2)
  41  	BEGIN
  42  		DECLARE @sql varchar(300)
  43  		select @sql = 'Exec sp_recompile ' + @RecompilableItem
  44  		print @sql
  45  		exec (@sql)
  46  	END
  47  	FETCH NEXT FROM RecompilableItemsCursor INTO @RecompilableItem
  48  END
  49  
  50  CLOSE RecompilableItemsCursor
  51  DEALLOCATE RecompilableItemsCursor
  52  
  53  
  54  GO
  55  

For Microsoft SQL (MSSQL).
Use this to clear the cache and buffers to ensure comparison are accurate.

   1  
   2  dbcc freeproccache
   3  go
   4  dbcc dropcleanbuffers
   5  go