Now that we know the API Gateway integration with the Lambda function works, we will deploy it and get the URL. The architecture is shown in the following diagram:

The workings of this architecture is as follows:

1. Sign in to the AWS Management Console and open the API Gateway console at https://console.aws.amazon.com/apigateway/.
2. In the Amazon API Gateway navigation pane, choose APIs and metrics.
3. Select Resources under metrics and /Vists/{resourceId}, and choose Deploy API from the Actions drop-down menu.
4. In the Deploy API pop-up window, perform the following steps:
   
   1. In Deployment stage, choose [New Stage]
   2. In Stage name, type prod
   3. In Stage description, type prod
   4. Select Deploy
5. The Stages under metrics should be automatically selected on the left-hand menu.
6. Select GET under prod/visits/{resourceId}/GET to get the invoke URL. The invoke URL should look like this: https://{restapi_id}.execute-api.{region}.amazonaws.com/prod/visits/{resourceId}.
7. Open a new browser tab and paste in the invoke URL: https://{restapi_id}.execute-api.{region}.amazonaws.com/Prod/visits/{resourceId}:
   • The response body will be {"message": "Internal server error"}
   • This is because we validated resource_id in the URL parse_parameters() function before querying DynamoDB to make sure that it is a number

8. Open a new browser tab and paste in the invoke URL: https://{restapi_id}.execute-api.{region}.amazonaws.com/prod/visits/324. As we have used the correct resourceId or EventId internally, you should see the following code in your browser tab:

      [{
           "EventCount": 3,
           "EventDay": 20171001,
           "EventId": "324"
      },
      {
           "EventCount": 5,
           "EventDay": 20171002,
           "EventId": "324"
      }]

9. Open a new browser tab and paste in the invoke URL: https://{restapi_id}.execute-api.{region}.amazonaws.com/Prod/visits/324?startDate=20171002. As we have added the startDate=20171002 parameter, you should see the following code in your browser tab:

      [{"EventCount": 5, "EventDay": 20171002, "EventId": "324"}]

That is using the other query_by_partition_and_sort_key() method in the Lambda with the startDate.

We now have a fully working serverless data API, with the ability to run different types of queries on DynamoDB.