Compare two EXCEL files to delete duplicate data using Powershell - excel

Question

I have a excel sheet that has number of columns and rows i need to delete all columns except one and delete all rows except predefined one(have an other excel sheet with one column and data(in rows) that are need to be deleted.
I have done the first that is to delete all the columns except, but i was only able to do that with Column number and i want to do this with Header name i.e. "Product Name" as Column number may change with other sheets.
Also want to do the same with Rows so i can compare row data from my reference execl.xlsx file and delete the one that are same.
$file = "C:\TE.xlsx" # here goes the path and name of the excel file.
$ColumnsToKeep = 4 # Specify the column numbers to delete.
$excel = New-Object -comobject Excel.Application # Creating object of excel in powershell.
$excel.DisplayAlerts = $False
$excel.visible = $False
$workbook = $excel.Workbooks.Open($file)
$sheet = $workbook.Sheets.Item(1) # Referring to first sheet.
$maxColumns = $sheet.UsedRange.Columns.Count
$ColumnsToRemove = Compare-Object $ColumnsToKeep (1..$maxColumns) | Where-Object{$_.SideIndicator -eq "=>"} | Select-Object -ExpandProperty InputObject
0..($ColumnsToRemove.Count - 1) | %{$ColumnsToRemove[$_] = $ColumnsToRemove[$_] - $_}
$ColumnsToRemove | ForEach-Object{
[void]$sheet.Cells.Item(1,$_).EntireColumn.Delete()
}
$workbook.SaveAs("C:\data1.XLSX")
$workbook.Close($true)
$excel.Quit()
[void][System.Runtime.Interopservices.Marshal]::ReleaseComObject($excel)
Remove-Variable excel

Answer 1

Provided all your columns have headers in the first row, you can use this:
$file = "C:\TE.xlsx"
$columnToKeep = 'product'
$excel = New-Object -ComObject Excel.Application
$excel.DisplayAlerts = $false
$excel.Visible = $false
$workbook = $excel.Workbooks.Open($file)
$sheet = $workbook.Worksheets.Item(1)
$maxColumns = $sheet.UsedRange.Columns.Count
# remove all columns except the one with header named $columnToKeep
for ($col = 1; $col -le $maxColumns; $col++) {
if ($sheet.Cells.Item(1, $col).Value() -ne $columnToKeep) {
[void]$sheet.Columns($col).EntireColumn.Delete()
}
}
$workbook.SaveAs("C:\data1.XLSX")
$workbook.Close($true)
$excel.Quit()
## clean-up used Com objects
$null = [System.Runtime.Interopservices.Marshal]::ReleaseComObject($sheet)
$null = [System.Runtime.Interopservices.Marshal]::ReleaseComObject($workbook)
$null = [System.Runtime.Interopservices.Marshal]::ReleaseComObject($excel)
[System.GC]::Collect()
[System.GC]::WaitForPendingFinalizers()