Azure Cosmos DB .NET SDK Version 3 Stream API with query example

CosmosStreamExample.cs

// Using the stream API to read data, in the context of an ASP.NET Web API
namespace CosmosWebAPI.Controllers
{
    [Produces("application/json")]
    [Route("api/ProductReview")]
    // GET: api/ProductReview/productId/continuationToken
    [HttpGet("{productId}/{continuationToken}", Name = "Get")]

    // using the new stream api
    public async Task<HttpResponseMessage> Query(string productId, string continuationToken)
    {
        var result = new HttpResponseMessage();

        // Read a single query page from Azure Cosmos DB as stream
        QueryDefinition query = new QueryDefinition("SELECT * FROM Reviews r WHERE r.productId = @id")
            .WithParameter("@id", productId);

        var queryIterator = this.container.GetItemQueryStreamIterator(query, continuationToken);
        var queryResponse = await queryIterator.ReadNextAsync();

        // Pass stream directly to response object, without deserializing
        result.StatusCode = queryResponse.StatusCode;
        result.Content = new StreamContent(queryResponse.Content);
        result.Headers.Add("continuationToken", queryResponse.Headers.ContinuationToken);

        return result;
    }
}

ReadNextAsync can return 0 results. Would it be better to show it looping until it get's a result?

When I run this it returns 0 results. Even though I have data in the Cosmos DB.

@Jeremywhiteley please look at the following samples to see how to fully drain the query. Empty pages are possible and expected. In most scenarios it just means the result for a single partition came back with 0 results. You need to full drain the query to check the rest of the partitions.

@Jeremywhiteley please look at the following samples to see how to fully drain the query. Empty pages are possible and expected. In most scenarios it just means the result for a single partition came back with 0 results. You need to full drain the query to check the rest of the partitions.

The above code should return data. Maybe I am confused. What would the Postman request look like?

This is what I get returned, but It does't have any data.

{
"Version": {
"Major": 1,
"Minor": 1,
"Build": -1,
"Revision": -1,
"MajorRevision": -1,
"MinorRevision": -1
},
"Content": {
"Headers": []
},
"StatusCode": 200,
"ReasonPhrase": "OK",
"Headers": [
{
"Key": "continuationToken",
"Value": [
""
]
}
],
"TrailingHeaders": [],
"RequestMessage": null,
"IsSuccessStatusCode": true
}

@j82w I am still finding it hard to stream the content directly without deserializing. I am getting the same result as @Jeremywhiteley. It'd be great if we have a working sample which we can leverage to stream data.

It's an exciting feature but without proper samples it's very hard to implement.

The working samples shared above doesn't have a proper sample to return from web api without intermediate serialization

@fazil1987 is there a github project to see a sample/project you are trying to use it in? Trying to understand what the problem is with the sample above. Is it the empty pages?