Book Image

Guide to NoSQL with Azure Cosmos DB

By : Gaston C. Hillar, Daron Yöndem
Book Image

Guide to NoSQL with Azure Cosmos DB

By: Gaston C. Hillar, Daron Yöndem

Overview of this book

Cosmos DB is a NoSQL database service included in Azure that is continuously adding new features and has quickly become one of the most innovative services found in Azure, targeting mission-critical applications at a global scale. This book starts off by showing you the main features of Cosmos DB, their supported NoSQL data models and the foundations of its scalable and distributed architecture. You will learn to work with the latest available tools that simplify your tasks with Cosmos DB and reduce development costs, such as the Data Explorer in the Azure portal, Microsoft Azure Storage Explorer, and the Cosmos DB Emulator. Next, move on to working with databases and document collections. We will use the tools to run schema agnostic queries against collections with the Cosmos DB SQL dialect and understand their results. Then, we will create a first version of an application that uses the latest .NET Core SDK to interact with Cosmos DB. Next, we will create a second version of the application that will take advantage of important features that the combination of C# and the .NET Core SDK provides, such as POCOs and LINQ queries. By the end of the book, you will be able to build an application that works with a Cosmos DB NoSQL document database with C#, the .NET Core SDK, LINQ, and JSON.
Table of Contents (13 chapters)
Title Page
Packt Upsell

Retrieving a POCO with a LINQ asynchronous query

Now open the Program.cs file and add the following using statements after the last line that declares a using statement: using System.Threading.Tasks;. The code file for the sample is included in the learning_cosmos_db_06_01 folder in the SampleApp1/SampleApp1/Program.cs file:

using System.Collections.Generic; 
using SampleApp1.Models; 
using SampleApp1.Types; 

Add the following static field to the Program class after the code that declares the client static field: private static DocumentClient client;. In this new version, we will save the Uri instance for the document collection in this field to reuse it in all the methods that require the collection URI:

private static Uri collectionUri;



The following lines declare the code for the GetCompetitionByTitleWithLinq asynchronous static method that builds a LINQ query to retrieve a Competition instance with a specific title from the document collection. The code is the LINQ version of the existing...