Powershell example

AddSiteColumnsToContentTypes.ps1

# 
# Description: 
#
# This script adds Site Columns to the appropriate Content Types as listed in 
# the AddSiteColumnsToContentTypes.csv. The .CSV needs to be saved to
# "C:\PowerShell\" directory. If this directory does not exist, you will need to create it.
#
# Running this script requires running PowerShell with elevated privileges so right
# click the SharePoint 2010 Management Shell and select "Run as administrator" then use
# change directory commands and tabs to run the PS1 from its directory.

# Reference the CSV holding the Content Type values and begin the loop
$create = Import-Csv -path c:\PowerShell\AddSiteColumnsToContentTypes.csv
$create | ForEach-Object {

# Get the Site where the Site Columns will be added to Content Types
$site = Get-SPSite -Identity $($_.'SiteCollectionURL')
$web = $site.RootWeb

# Add Site Columns to Content Types
$ct=$web.ContentTypes["$($_.'ContentType')"]; 
$fieldAdd=$web.Fields["$($_.'SiteColumn')"]
$fieldLink=New-Object Microsoft.SharePoint.SPFieldLink($fieldAdd)
$ct.FieldLinks.Add($fieldLink);
$ct.Update()

# Dispose of the Web and Site objects and close the loop
$web.Dispose()
$site.Dispose()
}