[Fix] Category SELECT can now get Null values

pfbudget/database.py

@@ -75,7 +75,7 @@ WHERE date BETWEEN (?) AND (?)
 SELECT_TRANSACTIONS_BY_CATEGORY = """
 SELECT *
 FROM transactions
-WHERE category = (?)
+WHERE category IS (?)
 """
 
 SELECT_TRANSACTION_BY_PERIOD = """
@@ -183,6 +183,10 @@ class DBManager:
         logger.info(f"Get transactions by {period}")
         return self.__execute(SELECT_TRANSACTION_BY_PERIOD, period)
 
+    def get_uncategorized_transactions(self):
+        logger.info("Get uncategorized transactions")
+        return self.get_category(None)
+
     def export(self):
         filename = pathlib.Path(
             "@".join([self.db, datetime.datetime.now().isoformat()])