- Database namespace is now NadekoBot.Db

- Db related code is now in src/NadekoBot/Db
- Finished major part of the db refactor, but many optimizations are left to be made

src/NadekoBot/Db/Extensions/ClubExtensions.cs

@@ -0,0 +1,48 @@
+using System.Linq;
+using Microsoft.EntityFrameworkCore;
+using System.Collections.Generic;
+using NadekoBot.Db.Models;
+
+namespace NadekoBot.Db
+{
+    public static class ClubExtensions
+    {
+        private static IQueryable<ClubInfo> Include(this DbSet<ClubInfo> clubs)
+            => clubs.Include(x => x.Owner)
+                .Include(x => x.Applicants)
+                    .ThenInclude(x => x.User)
+                .Include(x => x.Bans)
+                    .ThenInclude(x => x.User)
+                .Include(x => x.Users)
+                .AsQueryable();
+        public static ClubInfo GetByOwner(this DbSet<ClubInfo> clubs, ulong userId)
+            => Include(clubs).FirstOrDefault(c => c.Owner.UserId == userId);
+        
+        public static ClubInfo GetByOwnerOrAdmin(this DbSet<ClubInfo> clubs, ulong userId)
+            => Include(clubs).FirstOrDefault(c => c.Owner.UserId == userId
+                                                                || c.Users.Any(u => u.UserId == userId && u.IsClubAdmin));
+
+        public static ClubInfo GetByMember(this DbSet<ClubInfo> clubs, ulong userId)
+            => Include(clubs).FirstOrDefault(c => c.Users.Any(u => u.UserId == userId));
+
+        public static ClubInfo GetByName(this DbSet<ClubInfo> clubs, string name, int discrim)
+            => Include(clubs).FirstOrDefault(c => c.Name.ToUpper() == name.ToUpper() && c.Discrim == discrim);
+
+        public static int GetNextDiscrim(this DbSet<ClubInfo> clubs, string name)
+            => Include(clubs)
+                .Where(x => x.Name.ToUpper() == name.ToUpper())
+                .Select(x => x.Discrim)
+                .DefaultIfEmpty()
+                .Max() + 1;
+
+        public static List<ClubInfo> GetClubLeaderboardPage(this DbSet<ClubInfo> clubs, int page)
+        {
+            return clubs
+                .AsNoTracking()
+                .OrderByDescending(x => x.Xp)
+                .Skip(page * 9)
+                .Take(9)
+                .ToList();
+        }
+    }
+}