Entity Framework Core Factory Pattern for Sql Server

Introduction

Factory Pattern for Entity Framework Core. It helps for multiple EF DbContext with this pattern. You can create readonly context and read-write with transaction.

How to use it

Important Inherit your dbcontext with EFDbContext

public partial class YourDbContext : EFDbContext
    {
        public YourDbContext(DbContextOptions<QuizDbContext> options)
            : base(options)
        {
        }
    }

Dependency Injection

services.AddSingleton<IDbFactory, DbFactory>(provider => new DbFactory(connectionString));

ServiceCollection Extension

Example 1 (No LoggerFactory)
	services.AddEfDbFactory(connectionString: Configuration.GetConnectionString("DbConnection"));

Example 2 (With LoggerFactory)
	services.AddEfDbFactory(connectionString: Configuration.GetConnectionString("DbConnection"), loggerFactory: MyLoggerFactory, enableSensitiveDataLogging: true);

Example 3 (With Options)
            services.AddEfDbFactory(new EfDbFactoryOptions
                                        {
                                            ConnectionString = Configuration.GetConnectionString("DbConnection"),
                                            LoggerFactory =  MyLoggerFactory,
                                            EnableSensitiveDataLogging = true
                                        });

Injection in your controller

private readonly IDbFactory _factoryConn;

public WriteController(IDbFactory factoryConn)
{
  _factoryConn = factoryConn ?? throw new ArgumentNullException(nameof(factoryConn));
}

ReadWrite Factory

public async Task CreateBook(int authorId, string title)
        {
            using var factory = await factoryConn.Create(IsolationLevel.Snapshot);
            var context = factory.For<BooksDbContext>();

            var book = new Book
            {
                Title = "New book",
                AuthorId = authorId
            };
            context.Book.Add(book);
            await context.SaveChangesAsync();
            factory.CommitTransaction();
        }

Readonly factory

public async Task<IEnumerable<Book>> GetAllBooks()
        {
            using var factory = await factoryConn.Create();
            var context = factory.For<BooksDbContext>();
            return context.Book.ToList();
        }

Testing

private const string _connString =
            "Server=localhost\\sqlexpress;Database=QuizDb;Integrated Security=True;Trusted_Connection=True;MultipleActiveResultSets=True;ConnectRetryCount=0";

private static async Task<IDbFactory> GetNoCommitFactoryAsync() => await new DbFactory(_connString).CreateNoCommit();

[Fact]
public async Task Test_NoCommitFactory_AutoRollBack()
{
    using (var fac = await GetNoCommitFactory())
    {
        var context = fac.For<TestDbContext>();

        var quiz = new Quiz() {Title = "Test 1"};
        context.Quiz.Add(quiz);
        await context.SaveChangesAsync();

        var q = Assert.Single(context.Quiz.ToList());
        Assert.NotNull(q);
        Assert.Equal("Test 1", q.Title);
    }

    using (var fac2 = await GetNoCommitFactory())
    {
        var context = fac2.For<TestDbContext>();
        Assert.Empty(context.Quiz.ToList());
    }
}

Sample Projects

You can find sample projects under Src/Samples