Create A .NET 5 App To Perform CRUD Operations On Azure Cosmos DB (SQL API) Using EF Core

In the ConfigureServices method we have to add the following lines of code to configure Cosmos DB with ApplicationDbContext

var accountEndpoint = Configuration.GetValue<string>("CosmosDb:Account");
var accountKey = Configuration.GetValue<string>("CosmosDb:Key");
var dbName = Configuration.GetValue<string>("CosmosDb:DatabaseName");
services.AddDbContext<ApplicationDbContext>(x => x.UseCosmos(accountEndpoint, accountKey, dbName));

Step 6 - Add Controller

In the Controllers folder add a new Controller class called VideogameController. Copy-paste the following code into class.

These are simple endpoints to show how we can easily use LINQ style queries to perform CRUD operations on the database using DbContext.

using AzureCosmosEFCoreCRUD.DBContext;
using AzureCosmosEFCoreCRUD.Models;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace AzureCosmosEFCoreCRUD.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class VideogameController : ControllerBase
    {
        private readonly ILogger _logger;
        private readonly ApplicationDbContext applicationDbContext;
        private readonly IConfiguration configuration;

        public VideogameController(ApplicationDbContext applicationDbContext, IConfiguration configuration, ILogger<VideogameController> logger)
        {
            this.applicationDbContext = applicationDbContext;
            this.configuration = configuration;
            _logger = logger;
        }
        [HttpGet("GetAllVideogames")]
        public async Task<ActionResult<IList<Videogames>>> GetAllVideogames()
        {
            try
            {
                var videogames = await applicationDbContext.Videogames.ToListAsync();
                if (videogames != null)
                {
                    return Ok(videogames);
                }
                return NotFound("No results found");
            }
            catch (Exception ex)
            {
                _logger.LogError(ex.Message);
                return StatusCode(500, "Some error occured while retrieving data");
            }
        }
        [HttpGet]
        public async Task<ActionResult<IList<Videogames>>> GetVideogamesByName(string name)
        {
            try
            {
                var videogames = await applicationDbContext.Videogames.FirstOrDefaultAsync(x => x.Name == name);
                if (videogames != null)
                {
                    return Ok(videogames);
                }
                return NotFound("No results found for "+name);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex.Message);
                return StatusCode(500, "Some error occured while retrieving data");
            }
        }
        [HttpGet("GetVideogameByCompanyName")]
        public async Task<ActionResult<IList<Videogames>>> GetVideogameByCompanyName(string name)
        {
            try
            {
                var videogames = await applicationDbContext.Videogames.Where(x => x.Company.Name == name).ToListAsync();
                if (videogames != null)
                {
                    return Ok(videogames);
                }
                return NotFound("No results found for " + name);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex.Message);
                return StatusCode(500, "Some error occured while retrieving data");
            }
        }
        [HttpPost]
        public async Task<ActionResult> AddVideogame(Videogames videogame)
        {
            try
            {
                await applicationDbContext.Videogames.AddAsync(videogame);
                await applicationDbContext.SaveChangesAsync();
                return Ok();
            }
            catch(Exception ex)
            {
                _logger.LogError(ex.Message);
                return StatusCode(500, "Some error occured while adding data");
            }
        }
        [HttpDelete]
        public async Task<ActionResult> DeleteVideogameByName(string name)
        {
            try
            {
                var videogame = await applicationDbContext.Videogames.FirstOrDefaultAsync(x => x.Name == name);
                if (videogame != null)
                {
                    applicationDbContext.Remove(videogame);
                    await applicationDbContext.SaveChangesAsync();
                    return Ok();
                }
                return NotFound();
            }
            catch (Exception ex)
            {
                _logger.LogError(ex.Message);
                return StatusCode(500, "Some error occured while deleting data");
            }
        }
        [HttpPut]
        public async Task<ActionResult> UpdateVideogameByName(Videogames data)
        {
            try
            {
                var videogame = await applicationDbContext.Videogames.FirstOrDefaultAsync(x => x.Name == data.Name);
                if (videogame != null)
                {
                    var itemBody = applicationDbContext.Videogames.WithPartitionKey(videogame.Id);
                    itemBody.FirstOrDefault().Platform = "XBOX";
                    applicationDbContext.Update(itemBody.FirstOrDefault());
                    await applicationDbContext.SaveChangesAsync();
                    return Ok();
                }
                return NotFound();
            }
            catch (Exception ex)
            {
                _logger.LogError(ex.Message);
                return StatusCode(500, "Some error occured while updating data");
            }
        }
    }
}

Summary

This is a very basic article to serve as a base for how to use EF Core to do CRUD operations on Azure Cosmos DB using .NET 5 REST API

Source Code: https://github.com/tanujgyan/AzureCosmosEFCoreCRUD