Two powershell functions for running SQL. The first runs a single file, the second runs all files within a directory.

SQL Server Powershell

#Runs A SQL Script
Function runSQLScript {
  param(
    [string]$db, # the sql db to use
    [string]$script, #the script to use
    [string]$outLog,
    [string]$errLog
  )

  if($db){#The things I do for pretty output...
    $db = " $db"
  }

  Write-Host "`nBegin SQL Processing of:$db $script`t$(currentUDate)"

  if($db){
    $db = "-d$db"
  }

  SQLCMD -E $db -i $script -r1 2>> $errLog 1>> $outLog
};

#Run all SQL Scripts within a directory
Function runAllSQLScripts  {
  param(
    [string]$db, # the sql db to use
    [string]$dir = (Get-Item -Path ".\" -Verbose).FullName, # the directory to to run all sql files in, defaults to CWD.  if you want to speci
    [string]$filter = '*.sql' #just incase someone wants to change the filter
  )
  $currDate = $(currentUDate)
  $outLog = "out.$currDate.log"
  $errLog ="err.$currDate.log"

  $files = Get-ChildItem  $dir -Filter *.sql
  ForEach ($file in $files){
    runSQLScript -db $db -script $dir\$file -outLog $outLog -errLog $errLog
  }
};

//unix epoch timestamp
Function currentUDate{
  return $([string]$(Get-Date -UFormat %s)).split('.')[0]
};

Added a bonus timestamp utility function