I include invoke-sqlcmd2.ps1
and write-datatable.ps1
from http://blogs.technet.com/b/heyscriptingguy/archive/2010/11/01/use-powershell-to-collect-server-data-and-write-to-sql.aspx. Calls to run SQL commands take the form: Invoke-sqlcmd2 -ServerInstance "<sql-server>" -Database <DB> -Query "truncate table <table>"
An example of writing the contents of DataTable variables to a SQL table looks like: $logs = (get-item SQLSERVER:\sql\<server_path>).ReadErrorLog()
Write-DataTable -ServerInstance "<sql-server>" -Database "<DB>" -TableName "<table>" -Data $logs
I find these useful when doing SQL Server database-related PowerShell scripts as the resulting scripts are clean and readable.