Microsoft Graph list children including grandchildren - microsoft-graph-api

Question

Is there a way to recursively include the content of the children (grandchild) in one request in the Microsoft Graph API?
I want to query folder /foo/ and also get the content of /foo/baar/ e.g /foo/baar/baz.txt.
IGraphServiceClient graphClient = GraphServiceClient
.builder()
.authenticationProvider(authProvider)
.buildClient();
IDriveItemCollectionPage children = graphClient
.drives("{drive-id}")
.items("{item-id}")
.children()
.buildRequest()
.expand("children")
.get();
Expanding the query using children returns a com.microsoft.graph.http.GraphFatalServiceException: Unexpected exception returned from the service.Error code: notSupported
This would significantly enhance the performance of my requests.
Edit: just created a feature request: List children including grandchildren

Answer 1

It is not possible with expand to get files more than 1 level. It is mentioned in Known Issues section of Microsoft Graph Api docs.
But we can get all files and folders recursively using search.
Search with q=''(empty query search), this will return all files and folder in the search scope. For scope specific search, refer to this answer. You can use parentReference key to sort out which file belongs to which folder.
Example 1: The following query retrieves all files and folders in the root scope
https://graph.microsoft.com/v1.0/me/drive/root/search(q='')?$select=name,id,parentReference
Example 2: To search in the folder named 'temp' located in root folder
https://graph.microsoft.com/v1.0/me/drive/root:/temp:/search(q='doc')?$select=name,id,parentReference
Limitations with search (as of now)
Files and folders that are created recently take some time to reflect in the search results as they need to be indexed. They are visible when you query for children but they won't appear in search results.
The empty query trick works only with OneDrive Business accounts but not with OneDrive Personal accounts. For OneDrive personal accounts, when you search with empty query, it returns an error message Search Query cannot be empty"
The scope specific search(eg: search within a specific folder) works with OneDrive Personal but not with OneDrive business accounts.