Compare-Object does not work properly
good day all, i trying find change in personnel list monthly. personnel data being saved csv files on first , last day of month. after trying find difference between 2 csv file below cmdlet; $a = import-csv c:\old_prs.csv $b = import-csv c:\new_prs.csv $result1 = compare-object $a $b -property logonname -passthru |select "name;logonname;mail;department" | export-csv c:\result.csv -notypeinformation note: if use "select inputobject" instead of " select "name;logonname;mail;department" " , program write "inputobject" cell a1 of "result.csv" file, nothing else. both csv files has same columns "name;logonname;mail;department" old_prs.csv below; name logonname mail department name1 logonname1 mail1 dp1 name2 logonname2 mail2 dp2 name3 logonname3 mail3 dp3 name4 logonname4 mail4 dp4 name5 logonname5 mail5 dp5 ...