Merge Two Groups in a Group Collection-CodePudding

I Need to Group two Grouped Object into one Group, see example:

Name    Count Group                                             
----    ----- -----                                             
4771343    89 {@{Id=4be956d4-c46e-4456-8666-7a642cc1e8f8;[...]}}
4771342    44 {@{Id=4be956d4-c46e-4456-8666-7a642cc1e8f8;[...]}}

I want to merge this Two Group into One Group with the values in both, like this:

Name    Count Group                                             
----    ----- -----                                             
4771343    133 {@{Id=4be956d4-c46e-4456-8666-7a642cc1e8f8;[...]}}

What I tried is:

a. Creating a custom GroupInfo Object, which have no constructor and can't created manually

b. Modify the Group manually is impossible as it's read-only

c. So, I Manually update the object like this:

$RelevantGroups = $Groups | ? Name -Match '4771342|4771343'
$TempGroup = $Groups[0]
$field = $TempGroup.GetType().GetField('name','static,nonpublic,instance')
$field.SetValue($TempGroup,"4771343")

$Collection = [System.Collections.ObjectModel.Collection[psobject]]::new()    
$Collection.Add($RelevantGroups.Group)

$field = $TempGroup.GetType().GetField('group','static,nonpublic,instance')
$field.SetValue($TempGroup,$Collection)

$field = $TempGroup.GetType().GetField('count','static,nonpublic,instance')
$field.SetValue($TempGroup,133)

But because it's a Reference Type it's update the original object, I can solve it with new object but it feels a mess...

Do you have any idea how to achieve this??

CodePudding user response：

You just need the grouping key to evaluate to the same number for both groups of input objects, which you can do with a property expression like this:

$Groups = $Filtered | Group-Object {
  if($_.MpnId -eq 4771342){
    4771343
  }
  else {
    $_.MpnId
  }
}

If you have multiple mappings like this, arrange them in a dictionary and use that to resolve the grouping key:

$mapping = @{
    '4771342' = '4771343'
    '1234567' = '2345678'
}

$Groups = $Filtered | Group-Object {
  $idAsString = "$($_.MpnId)"
  if($mappings.ContainsKey($idAsString)){
    $mappings[$idAsString]
  }
  else {
    $idAsString
  }
}

The reason I'm "stringifying" the ID value is to avoid type confusion in case MpnId contains integer values of a different type than [int] (in which case the ContainsKey() call might fail for the same two values)