feat: foreign key constraints and comments deleted when deleting posts

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 - Categories are now unique and required, enforced at the database level
 - Various database indexes were added for common lookup patterns for quick retrieval
+- Foreign key constraints were added to enforce data integrity at the database level when records are related to one another
+  - Due to this addition, comments of a post now get deleted when a post is deleted
 - Fixes various database field types and type validation on form submission to better align with the context they are used with
 - Fixes a bug that didn't show the dropdown chevrons for form-select fields when creating a post
 - Fixes a Bootstrap deprecation warning

src/app/Http/Controllers/PostController.php

@@ -227,15 +227,17 @@ public function update(Request $request, int $id): RedirectResponse
     }
 
     /**
-     * Delete a post.
+     * Delete a post and its associated comments.
      *
      * @param Request $request
      * @param int $id
      * @return RedirectResponse
      */
     public function delete(Request $request, int $id): RedirectResponse
     {
-        Post::find($id)->delete();
+        $post = Post::find($id);
+        $post->comments()->delete();
+        $post->delete();
 
         session()->flash('message', 'Post deleted.');
         return redirect('/');

src/database/migrations/2023_09_20_214931_add_foreign_keys.php

@@ -0,0 +1,63 @@
+<?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('comments', function (Blueprint $table) {
+            $table->bigInteger('user_id')->unsigned()->change();
+            $table->bigInteger('post_id')->unsigned()->change();
+
+            $table->foreign('user_id')->references('id')->on('users');
+            $table->foreign('post_id')->references('id')->on('posts');
+
+            $table->renameIndex('comments_post_id_index', 'comments_post_id_foreign');
+        });
+
+        Schema::table('posts', function (Blueprint $table) {
+            $table->bigInteger('user_id')->unsigned()->change();
+            $table->bigInteger('category_id')->unsigned()->change();
+
+            $table->foreign('user_id')->references('id')->on('users');
+            $table->foreign('category_id')->references('id')->on('categories');
+
+            $table->renameIndex('posts_category_id_index', 'posts_category_id_foreign');
+            $table->renameIndex('posts_user_id_index', 'posts_user_id_foreign');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('comments', function (Blueprint $table) {
+            $table->dropForeign('comments_user_id_foreign');
+            $table->dropForeign('comments_post_id_foreign');
+
+            $table->dropIndex('comments_user_id_foreign');
+            $table->renameIndex('comments_post_id_foreign', 'comments_post_id_index');
+        });
+
+        // Changes must be done separately from dropping indexes
+        Schema::table('comments', function (Blueprint $table) {
+            $table->integer('user_id')->change();
+            $table->integer('post_id')->change();
+        });
+
+        Schema::table('posts', function (Blueprint $table) {
+            $table->dropForeign('posts_user_id_foreign');
+            $table->dropForeign('posts_category_id_foreign');
+
+            $table->renameIndex('posts_category_id_foreign', 'posts_category_id_index');
+            $table->renameIndex('posts_user_id_foreign', 'posts_user_id_index');
+        });
+    }
+};