Can't create Model Diagram

[gurufordy]

Hi, I'm trying to visualise an existing DbContext and can't seem to get this working at all.

If I right click the project and select to view the Model Diagram, I get an error as below

System.ArgumentException: Error:
System.InvalidOperationException: No database provider has been configured for this DbContext. A provider can be configured by overriding the DbContext.OnConfiguring method or by using AddDbContext on the application service provider. If AddDbContext is used, then also ensure that your DbContext type accepts a DbContextOptions<TContext> object in its constructor and passes it to the base constructor for DbContext.
   at Microsoft.EntityFrameworkCore.Internal.DbContextServices.Initialize(IServiceProvider scopedProvider, IDbContextOptions contextOptions, DbContext context)
   at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider()
   at Microsoft.EntityFrameworkCore.DbContext.Microsoft.EntityFrameworkCore.Infrastructure.IInfrastructure<System.IServiceProvider>.get_Instance()
   at Microsoft.EntityFrameworkCore.Infrastructure.Internal.InfrastructureExtensions.GetService[TService](IInfrastructure`1 accessor)
   at Microsoft.EntityFrameworkCore.Infrastructure.AccessorExtensions.GetService[TService](IInfrastructure`1 accessor)
   at Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.CreateContext(Func`1 factory)
   at Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.CreateContext(String contextType)
   at ReverseEngineer20.EfCoreModelBuilder.BuildResult(String outputPath, Boolean generateDdl) in C:\Code\EFCorePowerTools\src\GUI\efpt\EFCoreModelBuilder.cs:line 39
   at ReverseEngineer20.Program.Main(String[] args) in C:\Code\EFCorePowerTools\src\GUI\efpt\Program.cs:line 44

Parameter name: processResult
   at EFCorePowerTools.Handlers.ModelAnalyzerHandler.Generate(String outputPath, Project project, GenerationType generationType) in C:\projects\efcorepowertools\src\GUI\EFCorePowerTools\Handlers\ModelAnalyzerHandler.cs:line 72

But my DbContext has what it needs, as below:

VS 2019 Community 16.6.5
2.4.51 of the PT extension
EF Core 3.1.6
Connecting to Azure Cloud SQL

Anything I've missed, just ask, but what's going wrong?

[ErikEJ]

You need to add OnConfiguring with a UseSqlServer with a dummy connection string, as a bare minimum. Or use the Nuget package to create from a DbContext instance

[gurufordy]

Erik, firstly I appreciate the quick response and getting your time. Keep up the good work!

I've seen the DGML Nuget package before, but I'm not great with exposing it outside of just right clicking in VS. I assumed it would ask me for a connstring on generation of the DGML, but will give the OnConfiguring a go now 👍

[gurufordy]

Awesome that's working now thanks Erik!