How to support GUID in Windows Azure Mobile services

Question

It is specifically mention that WAMS needs a int ID column to work in SQL Azure. However when developing enterprise apps over distributed databases, GUIDs are the preferred Primary key to have. How does one get around avoiding int ID column and support GUID?

If that cannot be done then how does one go about syncing data on the cloud from multiple standalone databases on various tablets/mobile the app using WAMS is running on?

Answer 1

An update on this issue - as of last week, the mobile services now support arbitrary strings as the ids for the column - check out this post for more information. You can now insert data with an 'id' value (which you couldn't before), so you can use a Guid value on insert. Also, if you don't send anything on the Id column on insert (or that value is set to null), the server will by default generate an unique identifier for the column.

Answer 2

At present, I don't think that its possible to use a GUID in the ID column. The documentation for the Mobile Services server side scripts specify that for the Delete function, the ID must be a javascript Number type. As far as I can see, all of the available sample code, and the code that you can download from the portal is quite explicit in using an integer type for the ID.

You'll have to come up with a way of generating a unique integer value whenever a new record is created. The example here uses a tick count in Insert script, which is probably OK for a low volume application, but it would need to be made more robust, perhaps by generating a number based on the user's identity and combining it with the tick count.

Answer 3

I'm a little late to this but I have found you can use a GUid as a primary key to a mobile services table. A couple of points though. Set the JSON property to lower case "id" and use a nullable guid, this allows inserting when there a default on the id column (NewId())

    [JsonProperty(PropertyName = "id")]
    public Guid? Id { get; set; }

Ash..