Why do we need System.Data.SqlTypes in .NET Core?

[B1Z0N]

1. From what I know it focuses solely on Microsoft SQL Server support types. And it's seems weird to me, why do we need this particular SQL in here, why omit PostgreSQL, MySQL, etc? I understand that it's microsoft and all things, but why adding this to standard library and not just as a side dependency?

2. And even if we take it as granted than it doesn't include any types to actually connect to the database, for that we need to install extra System.Data.SqlClient package from nuget.

I tried reading code and docs on it and haven't managed to find the answers. So what is the purpose?

[teo-tsirpanis]

These types are in the BCL mostly for historic reasons; they have been there since the beginning of .NET Framework. If it were redesigned today, perhaps they would have been in a separate package.

Which is the reason that System.Data.SqlClient which is bundled on .NET Framework was replaced by an out-of-band NuGet package called Microsoft.Data.SqlClient.

[MaceWindu]

Note that they also used by System.Data.SqlServerCe. While it is not .net core assembly, it works in .net core just fine (as there is no other option)