Hi,

I have a csv file which I need to read and export the data to a csv file. The resulting csv file will only include unique values for column A. The input csv file has many duplicates for column A which I need to remove. Is there a Unique option which i can use when running the Import-CSV cmdlet? Thanks for looking into this.

Input CSV file. 

This may not be the most efficient way to get the data, but you can do something like this.

$importedcsv = Import-Csv 'c:\temp\csv.csv'
$uniquecol1 = $importedcsv | Select-Object -Property col1 -unique
foreach ($item in $uniquecol1) {
    $importedcsv | Where-Object { $_.col1 -eq $item.col1 } | Select-Object -first 1
    }

And then export the data returned to a CSV. My testing CSV just looks like this (so you can see the column names, etc.).

col1,col2
1,1
1,2
1,3
2,4
2,5
3,6
3,7
3,8
3,9

And my output looks like this:

col1                                      col2                                    
----                                      ----                                    
1                                         1                                       
2                                         4                                       
3                                         6  

Import-Csv 'c:\temp\csv.csv'|group col1 | %{$_.group[0]} | export-Csv newcsv.csv

Hi Jrv,

That did not work. I only see one entry in the output csv and I am expecting to see more.

Import-Csv C:\PowerShell\PC9999993.csv | Select Node,Flags,Category,Device,Udata,Text | Export-Csv -Path C:\PowerShell\PC9999993_1.csv NoTypeInformation
Import-Csv C:\PowerShell\PC9999993_1.csv | Group col4 | %{$_.group[3]} | Export-Csv -Path C:\PowerShell\PC9999993_2.csv NoTypeInformation

Column 4 is the column which I need to evaluate and remove duplicate entries and export only the latest entry.

Thanks

I am only seeing the first entry of the input csv file on the output csv file. 

You did not follow my example.  TO get unique values you need to reference only $_.group[0] which contains the whole CSV line.

This is all you need:

Import-Csv C:\PowerShell\PC9999993_1.csv |
    Group col4 |
    %{$_.group[0]} |
    Export-Csv -Path C:\PowerShell\PC9999993_2.csv NoType