Fix a return type

src/api/database/mysql_connector.py

@@ -59,7 +59,7 @@ class _MySqlDbConnection(PythonDbConnection[MySQLConnection, MySQLCursor]):
         self._closed = True
         self._py_connection.close()
     
-    def get_transaction_begin_statements(self, writable: bool, isolation_level: TransactionIsolationLevel) -> PreparedStatement or str:
+    def get_transaction_begin_statements(self, writable: bool, isolation_level: TransactionIsolationLevel) -> list[PreparedStatement or str]:
         if writable:
             return [
                 f"SET SESSION TRANSACTION ISOLATION LEVEL {isolation_level.value}",

src/api/database/postgres_connector.py

@@ -90,7 +90,7 @@ source_function: {diagnostic.source_function}
         self._closed = True
         self._py_connection.close()
     
-    def get_transaction_begin_statements(self, writable: bool, isolation_level: TransactionIsolationLevel) -> PreparedStatement or str:
+    def get_transaction_begin_statements(self, writable: bool, isolation_level: TransactionIsolationLevel) -> list[PreparedStatement or str]:
         if writable:
             return [f"START TRANSACTION ISOLATION LEVEL {isolation_level.value}, READ WRITE"]
         else:

src/api/database/sqlite_connector.py

@@ -62,7 +62,7 @@ class SqLiteDbConnection(PythonDbConnection[Connection, Cursor]):
         self._closed = True
         self._py_connection.close()
     
-    def get_transaction_begin_statements(self, writable: bool, isolation_level: TransactionIsolationLevel) -> PreparedStatement or str:
+    def get_transaction_begin_statements(self, writable: bool, isolation_level: TransactionIsolationLevel) -> list[PreparedStatement or str]:
         return ["BEGIN DEFERRED TRANSACTION"]  # Transactions in SQLite are serializable by default
     
     def get_transaction_end_statement(self, commit: bool) -> PreparedStatement or str: