我可以将这些CSV文件合并为1个更大的CSV文件吗？

Question

My Old Bat file Copy F:\\File.hdr+F:*.csv F:\\FinalOutput.csv

the HDR file is a single entry file that has only header data for the CSV files

Is there a way to perform this in PowerShell (to combine all the CSV files into a single file)?

Here is my powershell script that doesn't work

$CSVFolder = 'F:\Input\';
$OutputFile = 'F:\Output\NewOutput.csv';    
$CSV= @();    
Get-ChildItem -Path $CSVFolder -Filter *.inv | ForEach-Object { 
    $CSV += @(Import-Csv -Path $CSVFolder\$_)
}    
$CSVHeader = Import-Csv 'F:\Input\Headings.hdr'    
$CSV = $CSVHeader + $CSV    
$CSV | Export-Csv -Path $OutputFile -NoTypeInformation -Force;

I get the list of FileNames that are exported and not the content of the Files. The script is also modifying the date/time stamp on my INV files. It shouldn't be doing that.

Answer 1

You can skip the whole CSV bit if you just append the files as you would before.

Something like this should work:

# First we create the new file and add the header.
get-content $headerfile | set-content $outputfile

# Then we get the input files, read them out with get-content 
# and append them to the output file (add-content).
get-childitem -path $csvfolder *.inv | get-content | add-content $outputfile

The CSV commandlets are handy if you want to be processing the CSV data in your script, but in your case simply appending the files will do the trick. Not bothering with the CSV conversion will be a lot faster as Powershell doesn't have to parse the CSV lines and create PS-objects. It's really fast with pure text though.

Another trick here is how the get-content and add-content are used in the pipeline. Since they are aware of the pipeline you can pass in file objects without having to use a foreach loop. This makes your statements a lot shorter.

Answer 2

How about:

get-childitem *.inv | foreach-object {
  import-csv $_ -header (get-content Headings.hdr)
} | export-csv NewOutput.csv -notypeinformation