Unable to build .Net .sqlproj using "dotnet" command line tool. Here's the error:
dotnet\sdk\3.1.300\Microsoft\VisualStudio\v11.0\SSDT\Microsoft.Data.Tools.Schema.SqlTasks.targets" was not found
I have installed SSDT tool but it's not available at the above location.
Note: It's buildings without any error using Visual Studio and MSBuild
How to build .sqlproj projects using “dotnet” tool?
Sorry but as I know this is not supported scenario for now. It's by design that dotnet cli can't build the Database Project with old-framework style project file.
As for the reason why it's buildings without any error using Visual Studio and MSBuild but failing using dotnet. Please check your SSDT installation path, it should be under pathC:\Program Files (x86)\Microsoft Visual Studio\2019\VSEditon\MSBuild\Microsoft\VisualStudio\v16.0\SSDT.
The SSDT is installed as a sub-module of MSBuild(VS build tools) or MSBuild from VS, so it works well when building it via VS/MSbuild. But dotnet cli won't know where to find this module which is under MSBuild folder's sub-folder, so it throws error.
There's once a discussion about this in github, in my opinion the feature to support build SQLProj via Dotnet hasn't come true. If you're interested in that feature, I suggest you can open a new ticket there to post your idea.