Entity Framework - The DbContext of type 'SampleContext' cannot be pooled because it does not have a single public constructor accepting a single parameter of type DbContextOptions.

I was looking at some ways to improve the performance of one of our applications. One of the things I wanted to try was to active DbContext pooling(https://bartwullems.blogspot.com/2018/03/entity-framework-core-20dbcontext.html).

Unfortunately after adding the following lines:

	services.AddDbContextPool<BloggingContext>(
	options => options.UseSqlServer(connectionString)
	);

view raw efcore20.cs hosted with ❤ by GitHub

the application started to fail with this exception message:

System.InvalidOperationException: The DbContext of type 'TargetSUContext' cannot be pooled because it does not have a single public constructor accepting a single parameter of type DbContextOptions.

   at Microsoft.EntityFrameworkCore.Internal.DbContextPool`1..ctor(DbContextOptions options)

   at Microsoft.Extensions.DependencyInjection.EntityFrameworkServiceCollectionExtensions.<>c__5`2.<AddDbContextPool>b__5_1(IServiceProvider sp)

   at lambda_method(Closure , IBuildSession , IContext )

Let’s take a look at my DbContext and indeed I had multiple constructors:

	public class SampleContext:DbContext
	{
	public SampleContext()
	{
	}
	public SampleContext(string connectionString)
	{
	_connectionString = connectionString;
	}
	public SampleContext(DbContextOptions<SampleContext> options) : base(options)
	{
	}
	//Removed other code
	}

view raw SampleContext.cs hosted with ❤ by GitHub

I don’t understand why Entity Framework cannot handle this, but I removed the other constructors to make EF happy…