Powershell Getting Error Cannot convert value "System.Xml.XPathNodeList" to type "System.Xml.XmlDocument

Question

I have following powershell code, which is selecting a xml node which has namespace.

$ns = new-Object System.Xml.XmlNamespaceManager $doc.NameTable
$ns.AddNamespace("dns", "http://www.nlog-project.org/schemas/NLog.xsd")
$obj3 = $doc.SelectNodes('//dns:nlog',$ns)

But I am getting following error:

Cannot convert value "System.Xml.XPathNodeList" to type "System.Xml.XmlDocument". Error: "The specified node cannot be inserted as the valid child of this node, because the specified node is the wrong type." At C:\MetacubeAutoBuildDeployment\PowershellScripts\PEStandAloneWebConfigReplace.ps1:15 char:1 + $obj3 = $doc.SelectNodes('//dns:nlog',$ns) + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : MetadataError: (:) [], ArgumentTransformationMetadataException + FullyQualifiedErrorId : RuntimeException

Is there any specific reason for this error? I Have to fetch the value of connectionString tag highlighted in the $doc. $doc Contains:


  
    
    
    
    
    
      
      
      
      
    
  
  
    
  
  
    
    
      
      
    
    
    
      
      
      
        
          
          
          
          
          
          
          
          
          
        
      
      
        
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
        
      
      
        
          
          
          
          
          
          
        
      
      
        
        
        System.Data.SqlClient
        **server=server;database=database;integrated security=False;User ID=userid;Password=password**
        
          insert into [CIEL].[DPR_JOBINSTANCEDETAILS] (
          JOBID, JOBINSTANCEID, STEPINSTANCEID,STEPID,LOGTYPE, MESSAGETYPE, MESSAGE, PARENTID,LOGGEDON
          )
          values (
          @JOBID, @JOBINSTANCEID, @STEPINSTANCEID, @STEPID, @LOGTYPE,@MESSAGETYPE, @MESSAGE, @PARENTID, @LOGGEDON
          );
        
        
        
        
        
        
        
        
        
        
      
      
        
        NLogConnection

G42 · Accepted Answer

You could use GetElementsByTagName as suggested by WOxxOm's comments. It's elegant. But potential issues could be caused by changing xml structure, re-ordering or multiple connectionStrings.

You could dot-index into the XML. The advantage is that it is more explicit. The disadvantage is that it is more explicit.

If you change the path to the connectionString this will need to be updated where as GetElementsByTagName will not. However this is better for explicitly defining the tag you are interesting in and to give you convenient access to the other pieces of information within that tag. I find it is generally more intuitive.

$dbdetails = $doc.configuration.nlog.targets.target | Where-Object {$_.name -eq "database"}
$dbdetails.ConnectionString

Your code did not give me the same error on PowerShell v5.1. I copied your code for $doc, assigning it to a variable using a here-string:

[xml]$doc = @"
    ...
"@

Edit:

Best of both worlds?

$dbdetails = $doc.GetElementsByTagName("target") | Where-Object {$_.name -eq "database"}

Get-Member, showing the accessible properties

Powershell Getting Error Cannot convert value "System.Xml.XPathNodeList" to type "System.Xml.XmlDocument

Answers (1)

Related Questions

Powershell Getting Error Cannot convert value &quot;System.Xml.XPathNodeList&quot; to type &quot;System.Xml.XmlDocument

Answers (1)

Related Questions

Powershell Getting Error Cannot convert value "System.Xml.XPathNodeList" to type "System.Xml.XmlDocument