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Use delta query to track changes in Microsoft Graph data

  • Článek

Delta query, also called change tracking, enables applications to discover newly created, updated, or deleted entities without performing a full read of the target resource with every request. Microsoft Graph applications can use delta query to efficiently synchronize changes with a local data store.

Using delta query helps you avoid constantly polling Microsoft Graph, as the app requests only data that changed since the last request. This pattern allows the application to reduce the amount of data it requests, thereby reducing the cost of the request and as such, likely limit the chances of the requests being throttled.

Use delta query to track changes in a resource collection

The typical call pattern is as follows:

  1. The application makes a GET request with the delta function on the desired resource. For example, GET https://graph.microsoft.com/v1.0/users/delta.

    Tip

    /delta is a shortcut for the fully qualified name /microsoft.graph.delta. Requests generated by Microsoft Graph SDKs use the fully qualified name.

  2. Microsoft Graph responds with the requested resource and a state token.

    a. If Microsoft Graph returns a @odata.nextLink URL, there are more pages of data to retrieve in the session, even if the current response contains an empty result. The application uses the @odata.nextLink URL to continue making requests to retrieve all pages of data until Microsoft Graph returns a @odata.deltaLink URL in the response.

    b. If Microsoft Graph returns a @odata.deltaLink URL, there's no more data about the existing state of the resource to return in the current session. For future requests, the application uses the @odata.deltaLink URL to learn about changes to the resource.

    c. A page can't contain both @odata.deltaLink and @odata.nextLink.

    Note

    The Microsoft Graph response in Step 2 includes the resources that currently exist in the collection. Resources that were deleted prior to the initial delta query aren't returned. Updates made before the initial request are summarized on the resource returned as its latest state.

  3. When the application needs to learn about changes to the resource, it uses the @odata.deltaLink URL it received in step 2 to make requests. The application can make this request immediately after completing step 2 or when it checks for changes.

  4. Microsoft Graph returns a response describing changes to the resource since the previous request, and either a @odata.nextLink URL or a @odata.deltaLink URL.

Note

  • Resources stored in Microsoft Entra ID (such as users and groups) support "sync from now" scenarios. This allows you to skip steps 1 and 2 (if you're not interested in retrieving the full state of the resource) and ask for the latest @odata.deltaLink instead. Append $deltatoken=latest to the delta function and the response will contain a @odata.deltaLink and no resource data. Resources in OneDrive and SharePoint also support this feature but require token=latest instead.
  • $select and $deltaLink query parameters are supported for some Microsoft Entra resources so that customers can change the properties they want to track for an existing @odata.deltaLink. Delta queries with both $select and $skiptoken aren't supported.

State tokens

A delta query GET response always includes a URL specified in a @odata.nextLink or @odata.deltaLink response header. The @odata.nextLink URL includes a $skiptoken, and a @odata.deltaLink URL includes a $deltatoken.

These tokens are opaque to the client app but important as follows:

  • Each token reflects the state and represents a snapshot of the resource in that round of change tracking.
  • The state tokens encode and include query parameters (such as $select) specified in the initial delta query request. Therefore, don't modify subsequent delta query requests to repeat these query parameters.
  • When carrying out delta query, you can copy and apply the @odata.nextLink or @odata.deltaLink URL to the next delta function call without having to inspect the contents of the URL, including its state token.

Optional query parameters

If a client uses a query parameter, it must be specified in the initial request. Microsoft Graph automatically encodes the specified query parameter into the @odata.nextLink or @odata.deltaLink in the response and in all subsequent @odata.nextLink or @odata.deltaLink URLs.

Note the general limited support of the following optional query parameters:

  • $orderby

    Don't assume a specific sequence of the responses returned from a delta query. Assume that the same item can show up anywhere in the @odata.nextLink sequence and handle that in your merge logic.

  • $top

    The number of objects in each page can vary depending on the resource type and the type of changes made to the resource.

For the message resource, see details for query parameters support in a delta query.

For the user and group resources, there are restrictions on using some query parameters:

  • $expand isn't supported.

  • $top isn't supported.

  • $orderby isn't supported.

  • If a $select query parameter is used, the parameter indicates that the client prefers to only track changes on the properties or relationships specified in the $select statement. If a change occurs to a property that isn't selected, the resource for which that property changed doesn't appear in the delta response after a subsequent request.

  • $select also supports manager and members navigation properties for users and groups respectively. Selecting those properties allows tracking of changes to user's manager and group memberships.

  • Scoping filters allow you to track changes to one or more specific users or groups, filtering only by object ID. For example, the following request returns changes for the groups matching the IDs specified in the query filter.

https://graph.microsoft.com/beta/groups/delta/?$filter=id eq '477e9fc6-5de7-4406-bb2a-7e5c83c9ae5f' or id eq '004d6a07-fe70-4b92-add5-e6e37b8acd8e'

Resource representation in the delta query response

  • Newly created instances of a supported resource are represented in the delta query response using their standard representation.

  • Updated instances are represented by their id with at least the updated properties, but other properties might be included.

  • Relationships on users and groups are represented as annotations on the standard resource representation. These annotations use the format propertyName@delta. The annotations are included in the response of the initial delta query request.

  • Removed instances are represented by their id and an @removed object. The @removed object might include additional information about why the instance was removed. For example, "@removed": {"reason": "changed"}. Possible @removed reasons can be changed or deleted.

    • changed indicates the item was deleted and can be restored from deletedItems.

    • deleted indicates the item is deleted and can't be restored.

      The @removed object can be returned in the initial delta query response and in tracked (@odata.nextLink) responses. For example, a deleted directory object that can still be restored from deleted items shows up as "@removed": {"reason": "changed"}. Clients using delta query requests should be designed to handle these objects in the responses.

  • Instances restored from deletedItems show up as newly created instances in the delta query response.

Note

A single entity can be contained multiple times in the response, if that entity was changed multiple times and under certain conditions. Delta queries enable your application to list all the changes, but can't ensure that entities are unified in a single response.

Supported resources

Delta query is currently supported for the following resources. Some resources that are available in v1.0 have their corresponding delta functions still in preview status, as indicated.

Note: The delta function for resources marked with an asterisk (*) are only available on the /beta endpoint.

Resource collection API
application application: delta function
administrativeUnit administrativeUnit: delta function
callRecording callRecording: delta function
callTranscript callTranscript: delta function
chatMessage chatMessage: delta function
device device: delta function
directoryRole directoryRole: delta function
directoryObject directoryObject: delta function
driveItem 1 driveItem: delta function
educationAssignment educationAssignment: delta function
educationCategory educationCategory: delta function
educationClass educationClass: delta function
educationSchool educationSchool: delta function
educationUser educationUser: delta function
event event: delta function
group group: delta function
listItem 1 listItem: delta function
mailFolder mailFolder: delta function
message message: delta function
orgContact orgContact: delta function
oAuth2PermissionGrant oAuth2PermissionGrant: delta function
contactFolder contactFolder: delta function
contact resource contact: delta function
plannerBucket * plannerBucket: delta function
plannerUser 2 plannerUser: delta function
sites delta function of the site resource
servicePrincipal servicePrincipal: delta function
todoTask todoTask: delta function
todoTaskList todoTaskList: delta function
user user: delta function

Note

1 The usage pattern for OneDrive and SharePoint resources is similar to the other supported resources with some minor syntax differences. For more information about the current syntax, see driveItem: delta and listItem: delta.

2 The usage pattern for Planner resources is similar to other supported resources with a few differences. For more information, see planner: delta.

National clouds

Delta queries for supported resources are available for customers hosted on the public cloud, Microsoft Cloud for US Government, and Microsoft Cloud China operated by 21Vianet.

Limitations

Changes to properties stored outside the main data store aren't tracked

Some resources contain properties that are stored outside the main data store for the resource. For example, the user resource data is mostly stored in Microsoft Entra ID, but some of its properties, like skills, are stored in SharePoint Online. Currently, only the properties stored in the main data store trigger changes in the delta query; properties stored outside the main data store aren't supported as part of change tracking. Therefore, a change to any of these properties doesn't result in an object showing up in the delta query response.

For more information about properties stored outside of the main data store, see the users and groups documentation.

Processing delays

Expect varying delays between the time a resource instance changes, and the time the tracked change is reflected in a delta query response.

Sometimes, due to replication delays, the changes to the object might not show up immediately when you select the @odata.nextLink or the @odata.deltaLink. Retry the @odata.nextLink or @odata.deltaLink after some time to retrieve the latest changes.

Replays

Your application must be prepared for replays, which occur when the same change appears in subsequent responses. While delta query makes a best effort to reduce replays, they're still possible.

Synchronization reset

Delta query can return a response code of 410 Gone and a Location header containing a request URL with an empty $deltatoken (same as the initial query). This status usually happens to prevent data inconsistency due to internal maintenance or migration of the target tenant, and is an indication that the application must restart with a full synchronization of the target tenant.

Token duration

Delta tokens are only valid for a specific period before the client application needs to run a full synchronization again.

  • For directory objects, the limit is seven days.
  • For education objects (educationSchool, educationUser, and educationClass), the limit is seven days.
  • For Outlook entities (message, mailFolder, event, contact, contactFolder, todoTask, and todoTaskList), the upper limit isn't fixed; it's dependent on the size of the internal delta token cache. While new delta tokens are continuously added in the cache, after the cache capacity is exceeded, the older delta tokens are deleted.

In case the token expires, the service should respond with a 40X-series error with error codes such as syncStateNotFound. For more information, see Error codes in Microsoft Graph.

Combine delta query and change notifications

An app can use Microsoft Graph change notifications to subscribe to be notified when a specific resource changes. The application can then use delta query to request all changes since the last time it made the request.

Applications can use this strategy to nearly eliminate (only for supported resources) the need to frequently poll Microsoft Graph and process those changes to keep a local data store in sync, greatly reducing the chances for their requests to be throttled.

Related content

Learn more about delta query in the following tutorials: