sql - Powershell Error - Null/Empty Argument -

i have small powershell script meant column servername remote sql database called, hal0test > table, serverlist. however, can not figure out powershell error.

newest code:

write-output " `n start of hal0 `n";  $connectionstring = "server=qautilitydb01;database=hal0test;integrated security=true;" $connection = new-object system.data.sqlclient.sqlconnection $connection.connectionstring = $connectionstring $connection.open() $command = $connection.createcommand()  $serverarray = [system.collections.arraylist]@() $query = "select servername serverlist" $command.commandtext = $query $servernames = $command.executereader()  $table = new-object “system.data.datatable” $table.load($servernames)  $serverarray = $table | select -expand servername  $serverarray | foreach-object {     # $server returns each server name     $os    = get-wmiobject -class win32_operatingsystem -computer $_     $disks = get-wmiobject -class win32_logicaldisk -computer $_ |              where-object {$_.drivetype -eq 3} |              foreach-object {                  '{0} {1:d} mb free/{2:d} mb used' -f $_.deviceid,                      [int]($_.freespace/1mb), [int]($_.size/1mb)              }      new-object -type pscustomobject -property @{       'fqdn'            = $_       'servername'      = $os.pscomputername       'operatingsystem' = $os.caption       'disks'           = $disks -join ' | '     }     $command.commandtext = "update serverlist set fqdn = '$_', os = '$os.caption' servername = '$os.pscomputername';"     $result = $command.executenonquery()   } | export-csv 'c:\users\king\desktop\halo\output.csv' -delimiter '|' -notype write-output "`n end of hal0"; 

sql table:

you changed foreach-object loop foreach loop. if want use latter need change current object variable $_ loop variable $server:

foreach ($server in $serverarray) {   $os    = get-wmiobject -class win32_operatingsystem -computer $server   $disks = get-wmiobject -class win32_logicaldisk -computer $server | ...    ... }

otherwise need change loop foreach-object loop:

$serverarray | foreach-object {   $os    = get-wmiobject -class win32_operatingsystem -computer $_   $disks = get-wmiobject -class win32_logicaldisk -computer $_ | ...    ... }

also, there's no pipe between } , export-csv:

    $result = $command.executenonquery()   } export-csv 'c:\users\mdaraghmeh\desktop\halo\output.csv' -delimiter '|' -notype  ^ here 

and if there foreach loop still unable feed output pipeline. if want use foreach pipeline must assign output variable:

$output = foreach ($server in $serverarray) { ... } $output | export-csv ... 

or run in expression:

(foreach ($server in $serverarray) { ... }) | export-csv ... 

for direct pipeline processing need foreach-object loop:

$serverarray | foreach-object { ... } | export-csv ...