Azure Cosmos DB supports GROUP BY for queries for SQL (Core) API
Published date: November 27, 2019
In response to user requests, Azure Cosmos DB now supports GROUP BY for queries for SQL (Core) API. Use GROUP BY to run queries that group your results according to the values of one or more specified properties. This feature is currently supported in Data Explorer, JavaScript SDK 3.4, and .NET SDK 3.3. Support for other SDKs will be available later in 2019.