Powershell Data.Table - powershell

Question

Can anyone give some help with powershell tables?
The working part of the script
Function CheckWMI {
Param (
[Parameter(Mandatory=$True)]
$Computers
)
$CheckWMIResults = New-Object system.Data.DataTable
$Function = $CheckWMIResults.columns.add("ComputerName", [System.Type]::GetType("System.String") )
$Function = $CheckWMIResults.columns.add("Attempts", [System.Type]::GetType("System.Int32") )
$Function = $CheckWMIResults.columns.add("Result", [System.Type]::GetType("System.String") )
ForEach ($Computer in $Computers) {
$CheckWMIResults.Rows.Add($Computer,"0","Incomplete")
}
}
CheckWMI "192.168.1.8","192.168.1.7","192.168.1.6"
As you can see it takes each of the ip addresses and create a separate row for them.
Now how can I select one of those rows and update it, such as the count column of the second row?

Answer 1

There is no need to use a data structure so heavy as a DataTable for this. All you need is a simple collection like an array and the generic PSObject. The following rewrites your script above, then sets the Result of the first computer to Complete:
Function CheckWMI {
Param (
[Parameter(Mandatory=$True)]
[string[]]$Computers
)
$CheckWMIResults = #();
ForEach ($Computer in $Computers) {
$TempResults = New-Object PSObject;
$TempResults | Add-Member -MemberType NoteProperty -Name "ComputerName" -Value $Computer;
$TempResults | Add-Member -MemberType NoteProperty -Name "Attempts" -Value 0;
$TempResults | Add-Member -MemberType NoteProperty -Name "Result" -Value "Incomplete";
$CheckWMIResults += $TempResults;
}
$CheckWMIResults;
}
$Results = CheckWMI -Computers "192.168.1.8","192.168.1.7","192.168.1.6"
$Results[0].Result = "Complete";
$Results;
If you do need type checking (which the DataTable gives you), define your own type.
add-type #"
public class WMIResults {
public string ComputerName;
public int Attempts;
public string Result;
}
"#
Function CheckWMI {
Param (
[Parameter(Mandatory=$True)]
[string[]]$Computers
)
$CheckWMIResults = #();
ForEach ($Computer in $Computers) {
$TempResults = New-Object WMIResults;
$TempResults.ComputerName = $Computer
$TempResults.Attempts = 0;
$TempResults.Result = "Incomplete";
$CheckWMIResults += $TempResults;
}
$CheckWMIResults;
}
$Results = CheckWMI -Computers "192.168.1.8","192.168.1.7","192.168.1.6"
$Results[0].Result = "Complete";
$Results;
See http://blogs.msdn.com/b/powershell/archive/2009/03/11/how-to-create-an-object-in-powershell.aspx and Get-Help Add-Type for more details on this second method ( you could use a struct instead of a class for trivial cases, but classes are generally a better idea).