Is it possible to iterate all lists in Sharepoint in search for a given Field?

Question

Is it possible to itterate all Lists in SharePoint to find out which ones use a custom Lookup field?

I have an application which is currently failing because the custom Lookup field was pointing to a redundant URL which was removed.

Answer 1

It is not clear from your question what kind of solution you are looking. My answer is code based and tested on SP 2010 platform.

So here is c# code (link):

    using(SPSite site = new SPSite("http://mysite"))
    {
            SPField fld = site.RootWeb.AvailableFields["[FIELD DISPLAY NAME]"]
            ICollection<SPFieldTemplateUsage> collection = fld.ListsFieldUsedIn();
            foreach (SPFieldTemplateUsage usage in collection)
            {
                SPWeb web = site.AllWebs[usage.WebID];
                SPList list = web.Lists[usage.ListID];
                // Do something here....
                web.Dispose();
            }
    }

or you can use something similar using PowerShell:

$siteUrl = "http://mysite"
$fieldDisplayName = "My Field"   
$site = Get-SPSite $siteUrl
$field = $site.RootWeb.AvailableFields[$fieldDisplayName]
$lists = $field.ListsFieldUsedIn()
$field.ListsFieldUsedIn() | ForEach-Object {
    $w = $site.AllWebs[$_.WebID]
    $l = $w.Lists[$_.ListID]
    Write-Host "Web:" $w.Title "List:" $l.Title "ListUrl:" $l.RootFolder.Url
}

So I am not iterating lists but instead I am using SPField.ListsFieldUsedIn method to find all field usages.

Answer 2

I think the line

$l = $web.Lists[$_.ListID]

should be

$l = $w.Lists[$_.ListID]