Compare Two CSVs, match the columns on 2 or more Columns, export specific columns from both csvs with powershell

Question

i Have 2 CSV\'s

left.csv

Ref_ID,First_Name,Last_Name,DOB
321364060,User1,Micah,11/01/1969
946497594,User2,Acker,05/28/1960
887327716,User3,Aco,06/26/1950         


        

Answer 1

You could create you own key from each csv, then add from each csv to a new hashtable using this key.

Step through this in a debugger (ISE or VSCode) and tailor it to what you need... Add appropriate error checking as you need depending on the sanity of your data. Some statements below are just for debugging so you can inspect what's happening as it runs.

# Ref_ID,First_Name,Last_Name,DOB
$csv1 = @'
321364060,User1,Micah,11/01/1969
946497594,User2,Acker,05/28/1960
887327716,User3,Aco,06/26/1950
588496260,User4,John,05/23/1960
565465465,User5,Jack,07/08/2020
'@

# First_Name,Last_Name,DOB,City,Document_Type,Filename
$csv2 = @'
User1,Micah,11/01/1969,Parker,Transcript,T4IJZSYO.pdf
User2,Acker,05/28/1960,,Transcript,R4IKTRYN.pdf
User3,Aco,06/26/1950,,Transcript,R4IKTHMK.pdf
User4,John,05/23/1960,,Letter,R4IKTHSL.pdf
'@

# hashtable
$data = @{}

$c1 = $csv1 -split "`r`n"
$c1.count

foreach ($item in $c1)
{
    $fields = $item -split ','
    $key = $fields[1]+$fields[2]+$fields[3]
    $key

    # add new hashtable for given key
    $data.Add($key, [ordered]@{})

    # add data from c1 to the hashtable
    $data[$key].ID = $fields[0]
    $data[$key].First = $fields[1]
    $data[$key].Last = $fields[2]
    $data[$key].DOB = $fields[3]
}

$c2 = $csv2 -split "`r`n"
$c2.count

foreach ($item in $c2)
{
    $fields = $item -split ','
    $key = $fields[0]+$fields[1]+$fields[2]
    $key

    # add data from c2 to the hashtable
    $data[$key].Type = $fields[4]
    $data[$key].FileName = $fields[5]
}

$data.Count

foreach ($key in $data.Keys)
{
    '====================='
    $data[$key]
}