feat: many category and sub can be in playlist

database/migrations/2026_05_31_110000_create_music_playlist_category_pivot_tables.php

@@ -0,0 +1,79 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('music_category_playlist', function (Blueprint $table) {
+            $table->id();
+            $table->foreignId('playlist_id')->constrained('music_playlists')->cascadeOnDelete();
+            $table->foreignId('category_id')->constrained('music_categories')->cascadeOnDelete();
+            $table->timestamps();
+
+            $table->unique(['playlist_id', 'category_id']);
+        });
+
+        Schema::create('music_subcategory_playlist', function (Blueprint $table) {
+            $table->id();
+            $table->foreignId('playlist_id')->constrained('music_playlists')->cascadeOnDelete();
+            $table->foreignId('subcategory_id')->constrained('music_subcategories')->cascadeOnDelete();
+            $table->timestamps();
+
+            $table->unique(['playlist_id', 'subcategory_id']);
+        });
+
+        // Backfill the new pivots from the existing single columns.
+        if (Schema::hasColumn('music_playlists', 'category_id')) {
+            DB::table('music_playlists')
+                ->whereNotNull('category_id')
+                ->orderBy('id')
+                ->select('id', 'category_id')
+                ->chunk(200, function ($rows) {
+                    $now = now();
+                    $insert = $rows->map(fn ($row) => [
+                        'playlist_id' => $row->id,
+                        'category_id' => $row->category_id,
+                        'created_at' => $now,
+                        'updated_at' => $now,
+                    ])->all();
+
+                    DB::table('music_category_playlist')->insertOrIgnore($insert);
+                });
+        }
+
+        if (Schema::hasColumn('music_playlists', 'subcategory_id')) {
+            DB::table('music_playlists')
+                ->whereNotNull('subcategory_id')
+                ->orderBy('id')
+                ->select('id', 'subcategory_id')
+                ->chunk(200, function ($rows) {
+                    $now = now();
+                    $insert = $rows->map(fn ($row) => [
+                        'playlist_id' => $row->id,
+                        'subcategory_id' => $row->subcategory_id,
+                        'created_at' => $now,
+                        'updated_at' => $now,
+                    ])->all();
+
+                    DB::table('music_subcategory_playlist')->insertOrIgnore($insert);
+                });
+        }
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('music_subcategory_playlist');
+        Schema::dropIfExists('music_category_playlist');
+    }
+};

database/migrations/2026_05_31_110100_drop_category_columns_from_music_playlists_table.php

@@ -0,0 +1,35 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('music_playlists', function (Blueprint $table) {
+            $table->dropForeign(['subcategory_id']);
+            $table->dropColumn('subcategory_id');
+
+            $table->dropForeign(['category_id']);
+            $table->dropColumn('category_id');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('music_playlists', function (Blueprint $table) {
+            $table->foreignId('category_id')->nullable()->after('id')
+                ->constrained('music_categories')->nullOnDelete();
+            $table->foreignId('subcategory_id')->nullable()->after('category_id')
+                ->constrained('music_subcategories')->nullOnDelete();
+        });
+    }
+};