Microsoft Graph only returning the first 100 Users

Question

I have the below code which returns all users based on a filter. The problem is it only returns 100 users but I know there are a lot more.

private List<User> GetUsersFromGraph()
{
    if (_graphAPIConnectionDetails == null) ReadParametersFromXML();
    if (graphServiceClient == null) graphServiceClient = CreateGraphServiceClient();

    var users = graphServiceClient
        .Users
        .Request()
        .Filter(_graphAPIConnectionDetails.UserFilter)
        .Select(_graphAPIConnectionDetails.UserAttributes)
        .GetAsync()
        .Result
        .ToList<User>();

    return users;
}

the method returns only 100 user objects. My Azure portal admin reports there should be closer to 60,000.

Answer 1

Most of the endpoints in Microsoft Graph return data in pages, this includes /users.

In order to retrieve the rest of the results you need to look through the pages:

private async Task<List<User>> GetUsersFromGraph()
{
    if (_graphAPIConnectionDetails == null) ReadParametersFromXML();
    if (graphServiceClient == null) graphServiceClient = CreateGraphServiceClient();

    // Create a bucket to hold the users
    List<User> users = new List<User>();

    // Get the first page
    IGraphServiceUsersCollectionPage usersPage = await graphClient
        .Users
        .Request()
        .Filter("filter string")
        .Select("property string")
        .GetAsync();

    // Add the first page of results to the user list
    users.AddRange(usersPage.CurrentPage);

    // Fetch each page and add those results to the list
    while (usersPage.NextPageRequest != null)
    {
        usersPage = await usersPage.NextPageRequest.GetAsync();
        users.AddRange(usersPage.CurrentPage);
    }

    return users;
}

One super important note here, this method is the lest performant way to retrieve data from Graph (or any REST API really). Your app will be sitting there for a long time while it downloads all this data. The proper methodology here is to fetch each page and process just that page before fetching additional data.