(B) Add CQRS bases

Clinics.Backend/Application/Abstractions/CQRS/Commands/ICommand.cs

+using MediatR;
+
+namespace Application.Abstractions.CQRS.Commands;
+
+// No response
+public interface ICommand : IRequest
+{
+}
+
+// With response
+public interface ICommand<TResponse> : IRequest<TResponse>
+{
+}

Clinics.Backend/Application/Abstractions/CQRS/Commands/ICommandHandler.cs

+using MediatR;
+
+namespace Application.Abstractions.CQRS.Commands;
+
+// No response
+public interface ICommandHandler<TCommand> : IRequestHandler<TCommand>
+    where TCommand : ICommand
+{
+}
+
+// With response
+public interface ICommandHandler<TCommand, TResponse>
+    : IRequestHandler<TCommand, TResponse>
+    where TCommand : ICommand<TResponse>
+{
+}
\ No newline at end of file

Clinics.Backend/Application/Abstractions/CQRS/Queries/IQuery.cs

+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Application.Abstractions.CQRS.Queries
+{
+    internal interface Interface1
+    {
+    }
+}

Clinics.Backend/Application/Abstractions/CQRS/Queries/IQueryHandler.cs

+using MediatR;
+
+namespace Application.Abstractions.CQRS.Queries;
+
+public interface IQueryHandler<TQuery, TResponse>
+    : IRequestHandler<TQuery, TResponse>
+    where TQuery : IQuery<TResponse>
+{
+}

Clinics.Backend/Application/Application.csproj

@@ -6,6 +6,10 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="MediatR" Version="12.4.0" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\Domain\Domain.csproj" />
   </ItemGroup>