blazor-calendar/BlazorApp/Data/CalendarService.cs

using System.Collections.Generic;
using System.Threading.Tasks;
using Microsoft.EntityFrameworkCore;

namespace BlazorApp.Data
{
    public class CalendarService
    {
        public static async Task<List<Calendar>> GetCalendars()
        {
            await using var context = new MyContext();
            return await context.Calendars.ToListAsync();
        }

        public static async Task<Calendar> GetCalendarById(int id)
        {
            await using var context = new MyContext();
            return await context.Calendars.FindAsync(id);
        }

        public static async Task CreateCalendar(Calendar calendar)
        {
            await using var context = new MyContext();
            await context.Calendars.AddAsync(calendar);
        }
    }
}