Retrieving latest inserted _id(ObjectId) in azure cosmos db(mongo db API)

Question

I would like to know if we can retrieve latest inserted _id(ObjectId) created by CosmosDb(mongoDb) on the same connection. (similar to SCOPE_IDENTITY() in sql server). Im inserting the document from azure functions using CosmosDb output binding.

Answer 1

Per my knowledge, there is no similar function like SCOPE_IDENTITY() of SQL Server in MongoDb API.

We can get the latest document via sorting Azure Cosmos DB's internal Timestamp (_ts) property, that is a number representing the number of elapsed seconds since January 1, 1970.

The query will be like:

db.YourCollection.find().sort({"_ts":1}]).limit(1)