Consider moving to Microsoft.Data.SqlClient

[divega]

ASP.NET Core includes a caching provider and tool that uses System.Data.SqlClient, and perhaps there are other ways ASP.NET Core depends on SqlClient that I am not aware of.

Now that Microsoft.Data.SqlClient is available in NuGet, and EF Core will be upgraded to it in 3.0, we could consider upgrading to it as well.

Although the two providers can coexist in the same application, it would ideal to avoid the duplication.

On the hand, Microsoft.Data.SqlClient should probably be considered even more of an out-of-band dependency than System.Data.SqlClient, in the sense that it doesn't build from source in CoreFx. Maybe additional caution is required because of this, and perhaps we should avoid including it the shared framework.

cc @DamianEdwards, @Eilon, @natemcmaster

[natemcmaster]

First I've heard of this new package. When do we recommend Microsoft.Data.SqlClient vs System.Data.SqlClient to our customers? What's the primary difference?

[divega]

Is the new version of SqlClient. All future development will happen on it and System.Data.SqlClient is going to be in maintenance.

It uses a new namespace and is fully out of band from both .NET Framework and .NET Core rather than type forwarding in .NET Framework.

In this preview, the main functional differences are for Always Encrypted on .NET Core, SQL Server UTF-8 , and Data Classification support.

More details are in the readme and release notes at https://github.com/dotnet/sqlclient/, and in the .NET Core 3.0 preview 5 announcement blog post.

[divega]

When do we recommend Microsoft.Data.SqlClient vs System.Data.SqlClient to our customers?

The idea is that we recommend it from now on, although existing applications that don’t need new functionality or optimizations can stay on System.Data.SqlClient.

[Eilon]

I added a card to our PM/engr sync https://github.com/orgs/aspnet/projects/22?fullscreen=true so we can discuss this week.

[blowdart]

@HaoK can you size this please?

[blowdart]

Taking this out of identity because we'll get it for free with EF

[natemcmaster]

The only non-test code in this repo which directly depends on System.Data.SqlClient is the dotnet-sql-cache command line tool. I think we need to re-evaluate this dependency. Everything that ships in the .NET Core SDK is supposed to be open-source and source-buildable for Linux distros. The plans for open sourcing Microsoft.Data.SqlClient are unclear at the moment, and I'm not sure if this dependency will make it into source-build by the 3.0 timeframe.

There is an assembly in aspnet/Extensions still using System.Data.SqlClient: Microsoft.Extensions.Caching.SqlServer. Unlike dotnet-sql-cache, this package doesn't have the same OSS or source-build requirements, so it might be easier to have this adopt the new version. @divega it's probably worth opening an issue on that repo too so we can discuss implications of updating that package separately.