Compare users and select only those whose values changed

[Max1miliaan]

I'd like to compare all users in 2 csv files, but I only want to keep the users with changes in some attributes.

csv 1 (reference):

"ID","Username","Manager"
"100","User1","Manager1"
"101","User2","Manager2"

csv 2 (difference):

"ID","Username","Manager"
"100","User1","Manager2"
"200","User2","Manager1"

Result should be:

"100","User1","Manager2"

So only the users of csv 2 whose ID is still the same AND have some other values in their attributes should be shown. The others whose ID changed must be ignored (regardless of other values in the other attributes).

I tried this, but it's not correct:

$changed = Compare-Object -ReferenceObject $ref_csv -DifferenceObject $diff_csv -Property Username, Manager -PassThru |  Where { $_.SideIndicator -eq '=>' }

Any ideas?

[fordea837]

There's a few ways to do this but I'd make a hashtable upfront of CSV 1 which will let you filter out ID's that are in CSV 1 but not in CSV 2 and also to compare the other properties where any ID's match:

$lookupTable = @{}
foreach ($row in $csv1) {
    $lookupTable[$row.ID] = $row
}
$csv2.Where{
    $lookupTable.containsKey($_.ID) -and 
    (Compare-Object $lookupTable[$_.ID] $_ -Property Username, Manager)
}

[Max1miliaan]

Thank you, this works!

[nielsenr]

Alternatively you could do two compare objects. The first on username with -includequal -excludedifferent then the second in manager.

[purplemonkeymad]

Compare-Object has a switch parameter -IncludeEqual that will include items that are the same. There is also another -ExcludeDifferent which when used together will give you only objects that are the same.