I have a many-to-many relationship between a model User and Picture. These are linked by a join table called Picturization. 

If I obtain a list of users of a single picture, i.e. picture.users -> how can I ensure that the result obtained is sorted by either creation of the Picturization row (i.e. the order at which a picture was associated to a user). How would this change if I wanted to obtain this in order of modification?

Thanks!

**Edit**
Maybe something like

```
picture.users.where(:order => "created_at")

```

* but this created\_at refers to the created\_at in picturization