ConvertFrom-Json : Cannot convert the JSON string because a dictionary that was converted from the string contains the duplicated keys

Question

The following JSON is getting returned from OData API service:

{
  "d": {
    "results": [
      {
        "FileSystemObjectType": 0,
        "Id": 1,
        "ContentTypeId": "0x0100BC97B2F575CB0C42B79549F3BABD32A8",
        "Title": "Nokia California",
        "Address": "200 South Matilda Avenue\nW Washington Ave\n94086 Sunnyvale, California\nUnited States of America",
        "ID": 1,
        "Modified": "2014-02-24T10:06:39Z",
        "Created": "2014-02-24T10:06:39Z",
        "AuthorId": 12,
        "EditorId": 12,
        "OData__UIVersionString": "1.0",
        "Attachments": false,
        "GUID": "d12aafad-502a-4968-a69e-36a7ea05ec80"
      }
    ]
  }
}

and saved as a string into variable named $data

An attempt to convert a JSON-formatted string to a custom object using ConvertFrom-Json cmdlet:

$results = $data | ConvertFrom-Json

gives the following error:

ConvertFrom-Json : Cannot convert the JSON string because a dictionary that was converted from the string contains the duplicated keys 'Id' and 'ID'.

Is there any way to convert the specified JSON-formatted string in PowerShell?

Answer 1

In PowerShell V1.0, or in PowerShell V2.0 when the JSON is too big, I still use a convertion to XML :

Add-Type -AssemblyName System.ServiceModel.Web, System.Runtime.Serialization
function Convert-JsonToXml
{
  PARAM([Parameter(ValueFromPipeline=$true)][string[]]$json)

  BEGIN
  { 
    $mStream = New-Object System.IO.MemoryStream 
  }

  PROCESS
  {
    $json | Write-String -stream $mStream
  }

  END
  {
    $mStream.Position = 0
    try
    {
       $jsonReader = [System.Runtime.Serialization.Json.JsonReaderWriterFactory]::CreateJsonReader($mStream,[System.Xml.XmlDictionaryReaderQuotas]::Max)
       $xml = New-Object Xml.XmlDocument
       $xml.Load($jsonReader)
       $xml
    }
    finally
    {
       $jsonReader.Close()
       $mStream.Dispose()
    }
  }
}

Using this code you can loop thru your items you can test :

$a = Get-Content C:\temp\jsontest.txt
$b.root.d.results.Item
$b.root.d.results.Item[7].Id[0].InnerText

---

(Edited)

In you case I would only replace the expected duplicate ID/Id

$data = Get-Content C:\temp\jsontest.txt -Raw
$datacorrected = $a -creplace '"Id":','"Id-minus":'
$psJsonIn = $datacorrected | ConvertFrom-Json

If really you've got unexpected duplicate you can write a function that trap the convertion error due to duplicated key and replace one.