implement two queries

dotnet/AipsCore/Application/Models/User/Query/GetUser/GetUserQuery.cs

@@ -0,0 +1,5 @@
+using AipsCore.Application.Abstract.Query;
+
+namespace AipsCore.Application.Models.User.Query.GetUser;
+
+public record GetUserQuery(string UserId) : IQuery<Infrastructure.Persistence.User.User>;

dotnet/AipsCore/Application/Models/User/Query/GetUser/GetUserQueryHandler.cs

@@ -0,0 +1,32 @@
+using AipsCore.Application.Abstract.Query;
+using AipsCore.Domain.Common.Validation;
+using AipsCore.Domain.Models.User.Validation;
+using AipsCore.Domain.Models.User.ValueObjects;
+using AipsCore.Infrastructure.Persistence.Db;
+using Microsoft.EntityFrameworkCore;
+
+namespace AipsCore.Application.Models.User.Query.GetUser;
+
+public class GetUserQueryHandler : IQueryHandler<GetUserQuery, Infrastructure.Persistence.User.User>
+{
+    private readonly AipsDbContext _context;
+
+    public GetUserQueryHandler(AipsDbContext context)
+    {
+        _context = context;
+    }
+    
+    public async Task<Infrastructure.Persistence.User.User> Handle(GetUserQuery query, CancellationToken cancellationToken = default)
+    {
+        var result = await _context.Users
+            .Where(u => u.Id.ToString() == query.UserId)
+            .FirstOrDefaultAsync(cancellationToken);
+
+        if (result is null)
+        {
+            throw new ValidationException(UserErrors.NotFound(new UserId(query.UserId)));
+        }
+
+        return result;
+    }
+}