Call parent's init before field initialisation, not after

data_diff/databases/mssql.py

@@ -176,6 +176,8 @@ class MsSQL(ThreadedDatabase):
     _mssql: Any
 
     def __init__(self, host, port, user, password, *, database, thread_count, **kw):
+        super().__init__(thread_count=thread_count)
+
         args = dict(server=host, port=port, database=database, user=user, password=password, **kw)
         self._args = {k: v for k, v in args.items() if v is not None}
         self._args["driver"] = "{ODBC Driver 18 for SQL Server}"
@@ -190,7 +192,6 @@ def __init__(self, host, port, user, password, *, database, thread_count, **kw):
             raise ValueError("Specify a default database and schema.")
 
         self._mssql = None
-        super().__init__(thread_count=thread_count)
 
     def create_connection(self):
         self._mssql = import_mssql()