Use get_prep_value to match Django docs [skip ci]

ankane · ankane · commit 1bad2e6f779b · 2023-05-13T12:31:52.000-07:00
diff --git a/pgvector/django/__init__.py b/pgvector/django/__init__.py
@@ -40,7 +40,7 @@ def get_prep_value(self, value):
         return to_db(value)
 
     def value_to_string(self, obj):
-        return to_db(self.value_from_object(obj))
+        return self.get_prep_value(self.value_from_object(obj))
 
 
 class IvfflatIndex(PostgresIndex):
