Altering table adding columns

Alter Table TableName

Add    [ColumnName1] [float] NULL,
           [ColumnName2] [nvarchar](50) NULL,
          

How to find trigger assosiated with a table ?

select 'alter table '+quotename(s.name)+'.'+quotename(object_name(o.parent_obj))+ ' disable trigger '+quotename(o.name)

from sys.sql_modules m

join sys.sysobjects o on m.object_id=o.id

join sys.schemas s on s.schema_id = o.uid

where o.type='tr'

and definition like '%TABLENAME%'

Formatting DateTime to Date in SQL

Select convert(varchar(10),GetDate(),101)

Output: 04/16/2009

Select convert(varchar(10),GetDate(),103)

Output: 16/04/2009

Executing a SQL script using ADO.NET

The following article is a good starting point

http://www.mattberther.com/2005/04/11/executing-a-sql-script-using-adonet/