Converting T4 from .Net Framework 4.8 to .Net 6.0

Question

I get the error "System.Data.Common 6" not found.

<#@ template debug="false" hostspecific="false" language="C#" #>
<#@ assembly name="System.Core" #>
<#@ assembly name="$(TargetDir)\Microsoft.Data.SqlClient.dll" #>
<#@ import namespace="System.Linq" #>
<#@ import namespace="System.Text" #>
<#@ import namespace="System.Collections.Generic" #>
<#@ import namespace="Microsoft.Data.SqlClient" #>
<#@ output extension=".txt" #>
<#
    SqlConnection conn = new SqlConnection("Server=Mars;initial catalog=IKA-PROD;TrustServerCertificate=True;Timeout=10;Trusted_Connection=True");
#>

This works in the same solution

using Microsoft.Data.SqlClient;
internal class Program
{
    private static void Main(string[] args)
    {
        SqlConnection conn = new SqlConnection("Server=Mars;initial catalog=IKA-PROD;TrustServerCertificate=True;Timeout=10;Trusted_Connection=True");
        conn.Open();
        SqlCommand cmd = conn.CreateCommand();
        conn.Close();
    }
}

Answer 1

Hello @Josef Fieseler ,

Welcome to Microsoft Q&A forum.

I checked the corresponding NuGet package System.Data.Common, and it seems that the latest released(11/15/2016) version is 4.3.0 not 6.0.0. I am thinking if any class that you are using is not supported for .NET 6.0.

Please try to install the latest version of .NET 6, update Visual Studio and Windows OS, check if this error disappears.

Sincerely,

Tianyu

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Answer 2

This is what I feared: (https://developercommunity.visualstudio.com/t/error-in-t4-you-must-add-a-reference-to-assembly-n/1300905)

Unfortunately, while T4 templates can be used with .NET Core projects, you cannot use .NET Core libraries in your T4 template because the T4 engine uses .NET Framework for transformation and loading and running .NET Core libraries. NET Core code is not possible.