Create external list with powershell

Param 
( 
 [string] $SiteUrl = $null
 
)

write-host "Adding Snapin"
Add-PsSnapin Microsoft.SharePoint.PowerShell
write-host "Added"

$BusinessListName = "BusinessList"
$ConfigListName = "Config"

try 

{ 


$spweb = Get-SPWeb $SiteUrl
$ListGUID = ""
$ListUrl = "Lists/{0}"
 
  Write-Host "Creating and Configuring SPListDataSource"
  $ds = New-Object -TypeName Microsoft.SharePoint.SPListDataSource
  $ListCollection = $spweb.Lists
  
   $ds.SetProperty("LobSystemInstance", "db")
   $ds.SetProperty("EntityNamespace", "Business")
   $ds.SetProperty("Entity", "BusinessList")
   $ds.SetProperty("SpecificFinder", "GetBusinessListRead Item")
   
    Write-Host "Checking for list instance existence"
    $list =  $spweb.Lists[$BusinessListName];

      if($list)
      {
      Write-Host "List exists - " + $BusinessListName + " - deleting the list"
      $list.Delete();
      }
      
      Write-Host "Creating " + $BusinessListName + " list with Data Source.."
    
        $ListGUID = $spweb.Lists.Add($BusinessListName, "", [String]::Format($ListUrl, $BusinessListName), $ds)
     $ListCollection[$ListGUID].Update();
     $spweb.Update();
     
       
    
     Write-Host "List created successfully.." + 
     $list =  $spweb.Lists[$ConfigListName];

     if($list)
     {
     Write-Host "List exists - Config - deleting the list"
     $list.Delete();
     }