原文參見：http://get-spscripts.com/2011/06/removing-features-from-content-database.html

Error Message:

[MissingFeature] Database [SharePoint_Content_Portal] has reference(s) to a missing feature: Id = [8096285f-1463-42c7-82b7-f745e5bacf29], Name = [My Feature], Description = [], Install Location = [Test-MyFeature]. The feature with Id 8096285f-1463-42c7-82b7-f745e5bacf29 is referenced in the database [SharePoint_Content_Portal], but is not installed on the current farm. The missing feature may cause upgrade to fail. Please install any solution which contains the feature and restart upgrade if necessary.
 

從錯誤資訊中可以看出，名為“SharePoint_Content_Portal”的資料庫中的一個feature，並沒有安裝在SharePoint farm中或者曾經安裝過，但是已經被移除了。通常情況下，在移除solution的時候，會自動禁用feature，然後再移除solution，但是有些情況下，移除得並不乾淨，例如web application 級別的feature，或者沒有移除自定義的event receiver或者webpart等等。

下面的powershell可以解決這個問題。

function Remove-SPFeatureFromContentDB($ContentDb, $FeatureId, [switch]$ReportOnly)
{
    $db = Get-SPDatabase | where { $_.Name -eq $ContentDb }
    [bool]$report = $false
    if ($ReportOnly) { $report = $true }
    
    $db.Sites | ForEach-Object {
        
        Remove-SPFeature -obj $_ -objName "site collection" -featId $FeatureId -report $report
                
        $_ | Get-SPWeb -Limit all | ForEach-Object {
            
            Remove-SPFeature -obj $_ -objName "site" -featId $FeatureId -report $report
        }
    }
}

function Remove-SPFeature($obj, $objName, $featId, [bool]$report)
{
    $feature = $obj.Features[$featId]
    
    if ($feature -ne $null) {
        if ($report) {
            write-host "Feature found in" $objName ":" $obj.Url -foregroundcolor Red
        }
        else
        {
            try {
                $obj.Features.Remove($feature.DefinitionId, $true)
                write-host "Feature successfully removed from" $objName ":" $obj.Url -foregroundcolor Red
            }
            catch {
                write-host "There has been an error trying to remove the feature:" $_
            }
        }
    }
    else {
        #write-host "Feature ID specified does not exist in" $objName ":" $obj.Url
    }
}
 

有兩種方法使用以上程式碼，

1. 如果你只是想查詢哪些站點或者站點集中包含缺失的feature，使用如下方法：

Remove-SPFeatureFromContentDB -ContentDB "SharePoint_Content_Portal" -FeatureId "8096285f-1463-42c7-82b7-f745e5bacf29" –ReportOnly

這個方法會遍歷所有的站點，列出類似以下的內容：

Feature found in site : http://portal/site

2. 如果你想從資料庫中移除缺失的feature，可以使用下面的方法：

Remove-SPFeatureFromContentDB -ContentDB "SharePoint_Content_Portal" -FeatureId "8096285f-1463-42c7-82b7-f745e5bacf29"
 

這個方法會輸出類似如下的資訊：

Feature successfully removed from site : http://portal/site