Microsoft.Data.SqlClient NuGet is needed in some projects but others you can do using Microsoft.Data.SqlClient without the NuGet

Question

In some projects I need to add NuGet package Microsoft.Data.SqlClient to the project before I can do

using Microsoft.Data.SqlClient

In other projects, I can do that without explicitly adding the NuGet package. The examples below are both .NET 6.0 projects (same for .NET 5).

Referenced directly:

Not referenced directly:

I am wondering how this works. Is the package referenced indirectly somehow?

Answer 1

AspNetCore.HealthChecks.SqlServer depends on Microsoft.Data.SqlClient:

• .NETStandard 2.0
  • Microsoft.Data.SqlClient (>= 2.1.2)
  • Microsoft.Extensions.Diagnostics.HealthChecks (>= 5.0.1)
• net5.0
  • Microsoft.Data.SqlClient (>= 2.1.2)
  • Microsoft.Extensions.Diagnostics.HealthChecks (>= 5.0.1)

so as transitive dependency Microsoft.Data.SqlClient becomes available for you also.