How can subtract a character from csv using PowerShell - powershell

Question

I'm trying to insert my CSV into my SQL Server database but just wondering how can I subtract the last three character from CSV GID column and then assigned it to my $CSVHold1 variable.
My CSV file look like this
GID Source Type Message Time
KLEMOE http://google.com Od Hello 12/22/2022
EEINGJ http://facebook.com Od hey 12/22/2022
Basically I'm trying to get only the first three character from GID and pass that value to my $CSVHold1 variable.
$CSVImport = Import-CSV $Global:ErrorReport
ForEach ($CSVLine1 in $CSVImport) {
$CSVHold1 = $CSVLine1.GID | ForEach-Object { $_.$GID = $_.$GID.subString(0, $_.$GID.Length - 3); $_ }
$CSVGID1 = $CSVLine1.GID
$CSVSource1 = $CSVLine1.Source
$CSVTYPE1 = $CSVLine1.TYPE
$CSVMessage1 = $CSVLine1.Message
}
I'm trying to do like above but some reason I'm getting an error.
You cannot call a method on a null-valued expression.

Answer 1

Your original line 3 was/is not valid syntax as Santiago pointed out.
$CSVHold1 = $CSVLine1.GID | ForEach-Object { $_.$GID = $_.$GID.subString(0, $_.$GID.Length - 3); $_ }
You are calling $_.$GID but you're wanting $_.GID
You also don't need to pipe the object into a loop to achieve what it seems you are asking.
#!/usr/bin/env powershell
$csvimport = Import-Csv -Path $env:HOMEDRIVE\Powershell\TestCSVs\test1.csv
##$CSVImport = Import-CSV $Global:ErrorReport
ForEach ($CSVLine1 in $CSVImport) {
$CSVHold1 = $CSVLine1.GID.SubString(0, $CSVLine1.GID.Length - 3)
$CSVGID1 = $CSVLine1.GID
$CSVSource1 = $CSVLine1.Source
$CSVTYPE1 = $CSVLine1.TYPE
$CSVMessage1 = $CSVLine1.Message
Write-Output -InputObject ('Changing {0} to {1}' -f $CSVLine1.gid, $CSVHold1)
}
Using your sample data, the above outputs:
C:> . 'C:\Powershell\Scripts\dchero.ps1'
Changing KLEMOE to KLE
Changing EEINGJ to EEI
Lastly, be aware that that the SubString method will fail if the length of $CSVLine1.GID is less than 3.