Copy column of list to new column of same list in Sharepoint - sharepoint-2013

Question

I want to copy the whole column values to a new column.
As a solution, I prepare a workflow:
SET FIELD TO VALUE and make the workflow start when item update
But, I have 16000+ rows and to manually update each one is not possible as of now.
I also tried using Microsoft Flow but no success.
Could anyone please suggest a way to achieve it.

Answer 1

I would suggest PowerShell for such 'migration' work. Script from here,the script need to be run in SharePoint server.
Add-PSSnapin Microsoft.SharePoint.Powershell -ErrorAction SilentlyContinue
#Parameters
$SiteURL = "http://siteurl/"
$listName = "list"
$web = Get-SPweb $SiteURL
#Use the Display Names
$CopyFromColumnName = "Description" #column copy source
$CopyToColumnName = "Desc" #destination column
#Get the List
$list = $web.lists[$ListName]
#Get all Items
$Items = $list.Items
ForEach ($Item in $items)
{
#copy data from one column to another
$item[$copyToColumnName] = $item[$copyFromColumnName]
#Do a system update to avoid Version and to Keep same metadata
$item.SystemUpdate($false)
}
For SharePoint online, refer this thread, replace the iterate logic as pageing.
$Query = New-Object Microsoft.SharePoint.Client.CamlQuery
$Query.ViewXml = "<View Scope='RecursiveAll'><Query><OrderBy><FieldRef Name='ID' Ascending='TRUE'/></OrderBy></Query><RowLimit Paged='TRUE'>$BatchSize</RowLimit></View>"
$Counter = 0
#Batch process list items - to mitigate list threshold issue on larger lists
Do {
#Get items from the list
$ListItems = $List.GetItems($Query)
$Ctx.Load($ListItems)
$Ctx.ExecuteQuery()
$Query.ListItemCollectionPosition = $ListItems.ListItemCollectionPosition
#Loop through each List item
ForEach($ListItem in $ListItems)
{
//to do copy field value
$Counter++
Write-Progress -PercentComplete ($Counter / ($List.ItemCount) * 100) -Activity "Processing Items $Counter of $($List.ItemCount)" -Status "Searching Unique Permissions in List Items of '$($List.Title)'"
}
} While ($Query.ListItemCollectionPosition -ne $null)