How to retrieve a small number of list items based on a property value using C# Graph API SDK?

Question

I need to retrieve list items from a document library. The list items are retrieved by looking at a specific property named "X-transaction" (I have no control over the name of the property). I have a CSOM client that retrieves these items just fine using a CAML query, but we're migrating to Graph and I need to port the code over.

I have a properly configured GraphServiceClient that I have verified can be used to retrieve the title of the doc library. I'm trying to understand how to formulate the query. Should I be using Drives[drive.Id] to obtain the list items, or Lists[list.Id]?

When I try using drives:

var docLib = await ctx
    .Sites[site.Id]
    .Drives
    .Request()
    .GetAsync();
var drive = docLib.FirstOrDefault(d => d.Name == "DocLibraryName");

var filterQuery = $"field/X_x002d_transaction eq '{transactionId}'";
var items = await ctx.Drives[drive.Id]
            .Items
            .Request()
            .Filter(filterQuery)
            .GetAsync();

I get a syntax error exception:

Status Code: BadRequest
Microsoft.Graph.ServiceException: Code: invalidRequest
Message: One of the provided arguments is not acceptable.
Inner error:
    Code: badArgument

I'm clearly misunderstanding the syntax here. How should this filter be formatted?

If I instead try to read from a list, I get a complaint that filters are not supported on lists. It appears that avenue is closed off: true or false?

Answer 1

I am assuming that you have correct graphclient object and permissions assigned to your app registrations with you. You can try below code chunk to filter the list/library:

var siteId = "your-site-id";
var driveId = "your-drive-id";
var fieldName = "X_x002d_transaction";
var fieldValue = "<filter-value>";

var queryOptions = new List<QueryOption>
{
    new QueryOption("$filter", $"{fieldName} eq '{fieldValue}'")
};

var items = await graphClient.Sites[siteId].Drives[driveId].Root.Children
        .Request(queryOptions)
        .GetAsync();

foreach (var item in items)
{
   Console.WriteLine(item.Name);
}