DiscordClient/DiscordDelete/DiscordContext.cs

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

namespace DiscordDelete
{
    public class DiscordContext : DbContext
    {
        private const string DataPath = "messages.db";
        public DbSet<GuildMessage> GuildMessages { get; set; }
        public DbSet<PrivateMessage> PrivateMessages { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) =>
            optionsBuilder.UseSqlite($"Data Source={DataPath}");
    }

    public class GuildMessage { }

    public class PrivateMessage { }
}