Refactor upgrade and verify commands.

app/Console/Commands/Correction/DeleteEmptyGroups.php

@@ -0,0 +1,68 @@
+<?php
+/**
+ * DeleteEmptyGroups.php
+ * Copyright (c) 2019 thegrumpydictator@gmail.com
+ *
+ * This file is part of Firefly III.
+ *
+ * Firefly III is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Firefly III is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Firefly III. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+namespace FireflyIII\Console\Commands\Correction;
+
+use Exception;
+use FireflyIII\Models\TransactionGroup;
+use FireflyIII\Models\TransactionJournal;
+use Illuminate\Console\Command;
+
+/**
+ * Class DeleteEmptyGroups
+ */
+class DeleteEmptyGroups extends Command
+{
+    /**
+     * The console command description.
+     *
+     * @var string
+     */
+    protected $description = 'Delete empty transaction groups.';
+    /**
+     * The name and signature of the console command.
+     *
+     * @var string
+     */
+    protected $signature = 'firefly-iii:delete-empty-groups';
+
+    /**
+     * Execute the console command.
+     *
+     * @throws Exception;
+     * @return mixed
+     */
+    public function handle(): int
+    {
+        //
+        $groups = array_unique(TransactionJournal::get(['transaction_group_id'])->pluck('transaction_group_id')->toArray());
+        $count  = TransactionGroup::whereNull('deleted_at')->whereNotIn('id', $groups)->count();
+        if (0 === $count) {
+            $this->info('No empty groups.');
+        }
+        if ($count > 0) {
+            $this->info(sprintf('Deleted %d empty groups.', $count));
+            TransactionGroup::whereNull('deleted_at')->whereNotIn('id', $groups)->delete();
+        }
+
+        return 0;
+    }
+}