diff --git a/database/migrations/2022_10_07_091406_flatten_entity_permissions_table.php b/database/migrations/2022_10_07_091406_flatten_entity_permissions_table.php
new file mode 100644
index 000000000..468f33248
--- /dev/null
+++ b/database/migrations/2022_10_07_091406_flatten_entity_permissions_table.php
@@ -0,0 +1,105 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Query\Builder;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+class FlattenEntityPermissionsTable extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        // Remove entries for non-existing roles (Caused by previous lack of deletion handling)
+        $roleIds = DB::table('roles')->pluck('id');
+        DB::table('entity_permissions')->whereNotIn('role_id', $roleIds)->delete();
+
+        // Create new table structure for entity_permissions
+        Schema::create('new_entity_permissions', function (Blueprint $table) {
+            $table->id();
+            $table->unsignedInteger('entity_id');
+            $table->string('entity_type', 25);
+            $table->unsignedInteger('role_id')->index();
+            $table->boolean('view')->default(0);
+            $table->boolean('create')->default(0);
+            $table->boolean('update')->default(0);
+            $table->boolean('delete')->default(0);
+
+            $table->index(['entity_id', 'entity_type']);
+        });
+
+        // Migrate existing entity_permission data into new table structure
+
+        $subSelect = function (Builder $query, string $action, string $subAlias) {
+            $sub = $query->newQuery()->select('action')->from('entity_permissions', $subAlias)
+                ->whereColumn('a.restrictable_id', '=', $subAlias . '.restrictable_id')
+                ->whereColumn('a.restrictable_type', '=', $subAlias . '.restrictable_type')
+                ->whereColumn('a.role_id', '=', $subAlias . '.role_id')
+                ->where($subAlias . '.action', '=', $action);
+            return $query->selectRaw("EXISTS({$sub->toSql()})", $sub->getBindings());
+        };
+
+        $query = DB::table('entity_permissions', 'a')->select([
+            'restrictable_id as entity_id',
+            'restrictable_type as entity_type',
+            'role_id',
+            'view'   => fn(Builder $query) => $subSelect($query, 'view', 'b'),
+            'create' => fn(Builder $query) => $subSelect($query, 'create', 'c'),
+            'update' => fn(Builder $query) => $subSelect($query, 'update', 'd'),
+            'delete' => fn(Builder $query) => $subSelect($query, 'delete', 'e'),
+        ])->groupBy('restrictable_id', 'restrictable_type', 'role_id');
+
+        DB::table('new_entity_permissions')->insertUsing(['entity_id', 'entity_type', 'role_id', 'view', 'create', 'update', 'delete'], $query);
+
+        // Drop old entity_permissions table and replace with new structure
+        Schema::dropIfExists('entity_permissions');
+        Schema::rename('new_entity_permissions', 'entity_permissions');
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        // Create old table structure for entity_permissions
+        Schema::create('old_entity_permissions', function (Blueprint $table) {
+            $table->increments('id');
+            $table->integer('restrictable_id');
+            $table->string('restrictable_type', 191);
+            $table->integer('role_id')->index();
+            $table->string('action', 191)->index();
+
+            $table->index(['restrictable_id', 'restrictable_type']);
+        });
+
+        // Convert newer data format to old data format, and insert into old database
+
+        $actionQuery = function (Builder $query, string $action) {
+            return $query->select([
+                'entity_id as restrictable_id',
+                'entity_type as restrictable_type',
+                'role_id',
+            ])->selectRaw("? as action", [$action])
+            ->from('entity_permissions')
+            ->where($action, '=', true);
+        };
+
+        $query = $actionQuery(DB::query(), 'view')
+            ->union(fn(Builder $query) => $actionQuery($query, 'create'))
+            ->union(fn(Builder $query) => $actionQuery($query, 'update'))
+            ->union(fn(Builder $query) => $actionQuery($query, 'delete'));
+
+        DB::table('old_entity_permissions')->insertUsing(['restrictable_id', 'restrictable_type', 'role_id', 'action'], $query);
+
+        // Drop new entity_permissions table and replace with old structure
+        Schema::dropIfExists('entity_permissions');
+        Schema::rename('old_entity_permissions', 'entity_permissions');
+    }
+}