I ran into this issue, found this question, but was not satisfied with the answers because they all seem to suffer if the data you are using contains a delimiter, which should remain quoted. Getting rid of the unneeded double quotes is a good thing.
The solution below appears to solve this issue for a general case, and for all variants that would cause issues.
I found this answer elsewhere, Removing quotes from CSV created by PowerShell, and have used it to code up an example answer for the SO community.
Attribution: Credit for the regex, goes 100% to Russ Loski.
Code in a Function, Remove-DoubleQuotesFromCsv
function Remove-DoubleQuotesFromCsv
{
param (
[Parameter(Mandatory=$true)]
[string]
$InputFile,
[string]
$OutputFile
)
if (-not $OutputFile)
{
$OutputFile = $InputFile
}
$inputCsv = Import-Csv $InputFile
$quotedData = $inputCsv | ConvertTo-Csv -NoTypeInformation
$outputCsv = $quotedData | % {$_ -replace `
'\G(?<start>^|,)(("(?<output>[^,"]*?)"(?=,|$))|(?<output>".*?(?<!")("")*?"(?=,|$)))' `
,'${start}${output}'}
$outputCsv | Out-File $OutputFile -Encoding utf8 -Force
}
Test Code
$csvData = @"
id,string,notes,number
1,hello world.,classic,123
2,"a comma, is in here","test data 1",345
3,",a comma, is in here","test data 2",346
4,"a comma, is in here,","test data 3",347
5,"a comma, is in here,","test data 4`r`nwith a newline",347
6,hello world2.,classic,123
"@
$data = $csvData | ConvertFrom-Csv
"`r`n---- data ---"
$data
$quotedData = $data | ConvertTo-Csv -NoTypeInformation
"`r`n---- quotedData ---"
$quotedData
# this regular expression comes from:
# http://www.sqlmovers.com/removing-quotes-from-csv-created-by-powershell/
$fixedData = $quotedData | % {$_ -replace `
'\G(?<start>^|,)(("(?<output>[^,"\n]*?)"(?=,|$))|(?<output>".*?(?<!")("")*?"(?=,|$)))' `
,'${start}${output}'}
"`r`n---- fixedData ---"
$fixedData
$fixedData | Out-File e:\test.csv -Encoding ascii -Force
"`r`n---- e:\test.csv ---"
Get-Content e:\test.csv
Test Output
---- data ---
id string notes number
-- ------ ----- ------
1 hello world. classic 123
2 a comma, is in here test data 1 345
3 ,a comma, is in here test data 2 346
4 a comma, is in here, test data 3 347
5 a comma, is in here, test data 4... 347
6 hello world2. classic 123
---- quotedData ---
"id","string","notes","number"
"1","hello world.","classic","123"
"2","a comma, is in here","test data 1","345"
"3",",a comma, is in here","test data 2","346"
"4","a comma, is in here,","test data 3","347"
"5","a comma, is in here,","test data 4
with a newline","347"
"6","hello world2.","classic","123"
---- fixedData ---
id,string,notes,number
1,hello world.,classic,123
2,"a comma, is in here",test data 1,345
3,",a comma, is in here",test data 2,346
4,"a comma, is in here,",test data 3,347
5,"a comma, is in here,","test data 4
with a newline","347"
6,hello world2.,classic,123
---- e:\test.csv ---
id,string,notes,number
1,hello world.,classic,123
2,"a comma, is in here",test data 1,345
3,",a comma, is in here",test data 2,346
4,"a comma, is in here,",test data 3,347
5,"a comma, is in here,","test data 4
with a newline","347"
6,hello world2.,classic,123