How to use PowerShell Where-Object to return TFS changesets that have no workitems assigned?

Question

I have the following PowerShell command to retrieve TFS changesets with associated workitems:

Get-TfsItemHistory "$/path" -Version "D01/12/10~" -Recursive 
  | Select ChangesetId -exp WorkItems 
  | Format-Table ChangesetId, Id, Title -Auto

However, I also need to see changesets that have no assigned workitem. I imagined I could do the following (modified as per suggestion below):

Get-TfsItemHistory "$/path" -Version "D01/12/10~" -Recursive 
  | Select ChangesetId -exp WorkItems 
  | Where-Object {$_.WorkItems -eq $null }

However this seems to ignore my where clause and returns the same list of changesets as the first command.

Thanks

Boz

Update:

As per suggestion below, I tried:

Get-TfsItemHistory "$/path" -Version "D01/12/10~" -Recursive 
  | Where-Object {$_.WorkItems -eq $null }

This doesn't return any rows. However swapping -eq for -ne does return rows (but not the ones I want obviously).

Answer 1

Select object returns only the fields you request. So you wouldn't see and object in the pipeline by the time it gets to where object if you use the where-object before select it should work.

Answer 2

The WorkItems field is actually a collection or workitems, so null check is wrong, but counting 0 items works:

Get-TfsItemHistory "$/path" -Version "D01/12/10~" -Recursive 
  | Where-Object {$_.WorkItems.Count -eq 0 }

Also, the order of Where and Select is important, as 'rerun' user pointed out above, thanks.

Boz