RVRNEXT-28 add further checks before manupulating db

src/Repository/TransactionRepository.php

@@ -3,6 +3,7 @@
 use Container;
 use Generator;
 use RVR\PersistentData\Model\Community;
+use RVR\PersistentData\Model\Currency;
 use RVR\PersistentData\Model\Transaction;
 use RVR\PersistentData\Model\User;
 use SokoWeb\Database\Query\Select;
@@ -36,6 +37,22 @@ class TransactionRepository
         return $select->count() > 0;
     }
 
+    public function isAnyCommon(): bool
+    {
+        $select = new Select(Container::$dbConnection, Transaction::getTable());
+        $select->where('payee_user_id', '=', null);
+
+        return $select->count() > 0;
+    }
+
+    public function isAnyForCurrency(Currency $currency): bool
+    {
+        $select = new Select(Container::$dbConnection, Transaction::getTable());
+        $select->where('currency_id', '=', $currency->getId());
+
+        return $select->count() > 0;
+    }
+
     public function getPagedByCommunity(Community $community, int $start, int $limit, bool $useRelations = false, array $withRelations = []): Generator
     {
         $select = new Select(Container::$dbConnection);