Unable to add item with a lookup column value using CAML query

Question

I have a PowerShell script that add's a new item to a list which has 2 lookup columns to different lists

first part of the script add's the item with the correct lookup value:

$ListLookupitem = $ListLookup.Items | where {$_["Title"] -eq "TEST789"}
    
$NewItem[$ColumnName] = [string]$ListLookupitem.ID + ";#" + $ListLookupitem.Title

But when I am using CAML query to get the 2nd Item from the next list using:

 $query = New-Object Microsoft.SharePoint.SPQuery

     $query.Query = "@
        <Where>
        <And>
        <Eq>
        <FieldRef Name='TESTCOLUME2'/>
        <Value Type='Text'>"TEST123"</Value>
        </Eq>
        <Eq>
        <FieldRef Name='TESTCOLUME1'/>
        <Value Type='Text'>"TEST345"</Value>
        </Eq>
        </And>
        </Where>";

     $ListLookup = $ListLookup.GetItems($query)
    
   $NewItem[$ColumnName2] = [string]$Lookupitem.ID + ";#" + $Lookupitem.Title

  $NewItem.Update()

it doesn't add anything into the lookup column. Reason I am using CAML query for 2nd part is the 2nd list has duplicate value for one of the columns. So, I am using CAML query to filter on 2nd list's columns.

Answer 1

Modify as this:

Add-PSSnapin Microsoft.SharePoint.Powershell -ErrorAction SilentlyContinue
 
#Variables
$WebURL="http://sp2016/sites/dev"
$ParentListName="List3" #Lookup Parent List
$ChildListName="List4" #List to add new lookup value


 
#Get Web and List objects
$Web = Get-SPWeb $WebURL
$ParentList = $Web.Lists.tryGetList($ParentListName)
$ChildList = $Web.Lists.tryGetList($ChildListName)
$query = New-Object Microsoft.SharePoint.SPQuery

 $query.Query = "@
    <Where>
    <And>
    <Eq>
    <FieldRef Name='TESTCOLUME2'/>
    <Value Type='Text'>TEST123</Value>
    </Eq>
    <Eq>
    <FieldRef Name='TESTCOLUME1'/>
    <Value Type='Text'>TEST345</Value>
    </Eq>
    </And>
    </Where>";

$Lookupitem = $ParentList.GetItems($query)

$NewItem=$ChildList.Items.Add()
$NewItem["Title"]="Dec 2014 Milestone"
$NewItem["ColumnName2"] = [string]$Lookupitem.ID + ";#" + $Lookupitem.Title
$NewItem.Update()  
 

write-host "Lookup Field value has been updated!"

If you are using some fixed value in CAML Query, no need to append "" and $ListLookup should be modified to $Lookupitem