EntityFrameworkCore.Parallel

This extension to Entity Framework Core adds a Set<TContext, TEntity>() method to IDbContextFactory<TContext>. For easy use it also adds a Parallel() method to IDbContextFactory<TContext> and a Set<TEntity>() method to IDbContextFactory<DbContext>. This allows you to easily execute multiple queries in parallel without the need to write complex code, or a lot of using blocks or statements. You can stick to all your known methods from IQueryable<TEntity>. As the context is disposed after your query is executed, all results will obviously not be tracked and disconnected from any DbContext.

How to use

In your Startup class, add a DbContextfactory. If you want a pooled one, or not is up to you.

services.AddPooledDbContextFactory<OrderContext>(options => options.UseSqlServer(@"Server=(localdb)\mssqllocaldb;Database=OrderTest"));

In your business class, inject an IDbContextFactory<TContext> and use it like this

var ordersFromDb = await _factory.Parallel().Set<Order>().Where(o => o.Id > 3).ToListAsync(cancellationToken);

Or like this

var ordersFromDb = await _factory.Set<MyContext, Order>().Where(o => o.Id > 3).ToListAsync(cancellationToken);

Migration from Entity Framework Core 5 to 6

Since Entity Framework Core 6, IDbContextFactory<TContext> is no longer covariant (TContext is not marked with the out keyword). Because of that, the following code does no longer work.

var ordersFromDb = await _factory.Set<Order>().Where(o => o.Id > 3).ToListAsync();

See the How to use section for two possibilities that you can use instead. If you want some background information, have a look at https://github.com/dotnet/efcore/issues/26630