Restructured the project structure back to the way it was, there's no reasonable way to split the modules

src/NadekoBot/Db/Extensions/QuoteExtensions.cs

@@ -0,0 +1,53 @@
+#nullable disable
+using Microsoft.EntityFrameworkCore;
+using Nadeko.Bot.Db.Models;
+
+namespace NadekoBot.Db;
+
+public static class QuoteExtensions
+{
+    public static IEnumerable<Quote> GetForGuild(this DbSet<Quote> quotes, ulong guildId)
+        => quotes.AsQueryable().Where(x => x.GuildId == guildId);
+
+    public static IReadOnlyCollection<Quote> GetGroup(
+        this DbSet<Quote> quotes,
+        ulong guildId,
+        int page,
+        OrderType order)
+    {
+        var q = quotes.AsQueryable().Where(x => x.GuildId == guildId);
+        if (order == OrderType.Keyword)
+            q = q.OrderBy(x => x.Keyword);
+        else
+            q = q.OrderBy(x => x.Id);
+
+        return q.Skip(15 * page).Take(15).ToArray();
+    }
+
+    public static async Task<Quote> GetRandomQuoteByKeywordAsync(
+        this DbSet<Quote> quotes,
+        ulong guildId,
+        string keyword)
+    {
+        return (await quotes.AsQueryable().Where(q => q.GuildId == guildId && q.Keyword == keyword).ToArrayAsync())
+            .RandomOrDefault();
+    }
+
+    public static async Task<Quote> SearchQuoteKeywordTextAsync(
+        this DbSet<Quote> quotes,
+        ulong guildId,
+        string keyword,
+        string text)
+    {
+        return (await quotes.AsQueryable()
+                            .Where(q => q.GuildId == guildId
+                                        && (keyword == null || q.Keyword == keyword)
+                                        && (EF.Functions.Like(q.Text.ToUpper(), $"%{text.ToUpper()}%")
+                                            || EF.Functions.Like(q.AuthorName, text)))
+                            .ToArrayAsync())
+               .RandomOrDefault();
+    }
+
+    public static void RemoveAllByKeyword(this DbSet<Quote> quotes, ulong guildId, string keyword)
+        => quotes.RemoveRange(quotes.AsQueryable().Where(x => x.GuildId == guildId && x.Keyword.ToUpper() == keyword));
+}