fix migration on mysql (#531)

Co-authored-by: Iurchenko Sergei <empty>

constance/migrations/0002_migrate_from_old_table.py

@@ -1,19 +1,25 @@
+from logging import getLogger
+
 from django.core.management.color import no_style
-from django.db import migrations, connection, DatabaseError
+from django.db import migrations, DatabaseError
+
+
+logger = getLogger(__name__)
 
 
 def _migrate_from_old_table(apps, schema_editor) -> None:
     """
     Copies values from old table.
     On new installations just ignore error that table does not exist.
     """
+    connection = schema_editor.connection
+    quoted_string = ', '.join([connection.ops.quote_name(item) for item in ['id', 'key', 'value']])
     try:
         with connection.cursor() as cursor:
-            cursor.execute('INSERT INTO constance_constance ( id, key, value ) SELECT id, key, value FROM constance_config', [])
+            cursor.execute(f'INSERT INTO constance_constance ( {quoted_string} ) SELECT {quoted_string} FROM constance_config', [])
             cursor.execute('DROP TABLE constance_config', [])
-
-    except DatabaseError:
-        pass
+    except DatabaseError as exc:
+        logger.exception('copy data from old constance table to a new one')
 
     Constance = apps.get_model('constance', 'Constance')
     sequence_sql = connection.ops.sequence_reset_sql(no_style(), [Constance])