Major update

venues/Handlers/GetVenueByIdQueryHandler.cs

@@ -0,0 +1,25 @@
+using System;
+using MediatR;
+using Microsoft.EntityFrameworkCore;
+using Venues.DbContexts;
+using Venues.Entities;
+using Venues.Queries;
+
+namespace Venues.Handlers
+{
+	public class GetVenueByIdQueryHandler : IRequestHandler<GetVenueByIdQuery, Venue>
+	{
+		private readonly VenuesContext _dbContext;
+
+		public GetVenueByIdQueryHandler(VenuesContext dbContext)
+		{
+			_dbContext = dbContext ?? throw new ArgumentNullException(nameof(dbContext));
+		}
+
+		public async Task<Venue> Handle(GetVenueByIdQuery request, CancellationToken cancellationToken)
+		{
+			return await _dbContext.Venues.Where(x => x.Id == request.VenueId).FirstOrDefaultAsync();
+		}
+	}
+}
+